Статті в журналах з теми "Pavements Australia Performance"

This study deals with the Austroads (2008) Guide to Pavement Technology Part 2: Pavement Structural Design on which most road pavement designs in Australia are based. Flexible pavement designs and performance predictions for pavements containing one of more bound layers derived from the mechanistic Austroads pavement design methodology and the AASHTO-2004 approach are compared for Australian conditions, with consideration of subgrade and other material properties and local design preferences. The comparison has been made through two well-known programs namely CIRCLY (5.0) and KENLAYER. The study shows that each guide has its own advantages and disadvantages in predicting stress and strain in pavement layers under different conditions. The study recommends that modifications are necessary resulting in more realistic and longer lasting pavements in Australia.

Shallow geothermal energy utilises the ground at relatively shallow depths as a heat source or sink to efficiently heat and cool buildings. Geothermal pavement systems represent a novel concept where horizontal ground source heat pump systems (GSHP) are implemented in pavements instead of purpose-built trenches, thus reducing their capital costs. This paper presents a geothermal pavement system segment (20m × 10m) constructed and monitored in the city of Adelaide, Australia, as well as thermal response testing (TRT) results. Pipes have been installed in the pavement at 0.5 m depth, and several thermistors have been placed on the pipes and in the ground. A TRT has been performed with 6kW heating load to achieve an understanding of the thermal response of the system as well as to estimate the effective thermal conductivity of the ground. The results show that the conventional semi-log method may be applicable to determine the thermal conductivity for geothermal pavements. The geothermal heat exchanger at shallow depth is considerably under the influence of the ambient temperature; however, it is still acceptable for exchanging the heat within the ground. It is also concluded that the impact radius of heat exchanger in geothermal pavement during the TRT is around 0.5m in the vertical and horizontal directions for this case study.

Pervious pavements are an effective stormwater treatment technology. However, their performance under variable drying and wetting conditions have yet to be tested, particularly under a continuous time scale. This paper reports on the clogging behaviour and pollutant removal efficiency of three pervious pavement types over 26 accelerated years. These pavements were monolithic porous asphalt (PA), Permapave (PP) and modular Hydrapave (HP). Over a cycle of 13 days, the period of which was equivalent to the average annual Brisbane, Australia rainfall (1,200 mm), the pavements were randomly dosed with four different flows. Drying events of 3 h duration were simulated during each flow. Inflow and outflow samples were collected and analysed for Total Suspended Solids (TSS), Total Phosphorus (TP) and Total Nitrogen (TN). To evaluate the rate of clogging, a 1 in 5 year Brisbane storm event was simulated in the 6th, 8th, 12th, 16th, 20th and 24th week. Under normal dosing conditions, none of the pavements showed signs of clogging even after 15 years. However, under storm conditions, both PA and HP started to clog after 12 years, while PP showed no signs of clogging after 26 years. The drying and various flow events showed no effects in TSS removal, with all systems achieving a removal of approximately 100%. The average TP removal was 20% for all flows except for low flow, which had a significant amount of leaching over time. Leaching from TN was also observed during all flows except high flow. The TSS, TP and TN results observed during storm events were similar to that of high flow.

New technology of reinforcement materials in asphalt overlays can offer a potentially cost effective solution for treating cracked pavements. To date, however, there is no design process allowing the use of available reinforcement products in road applications in Australia; whereas overseas design procedures are not readily available. A new 3D finite element (FE) analysis procedure was considered where reinforced asphalt layer is modelled as a thin 3D compound non-homogeneous layer which is then converted into a 3D orthotropic membrane. This procedure was used to analyse performance of three reinforcing products for road applications in Australia and results indicated that it is possible to predict and compare “retard reflection cracking” performance of various reinforced products.

Disruptive technology, especially autonomous vehicles, is predicted to provide higher safety and reduce road traffic emissions. Lane detection and tracking are critical building blocks for developing autonomous or intelligent vehicles. This study presents a lane detecting algorithm for autonomous vehicles on different road pavements (structured and unstructured roads) to overcome challenges such as the low detection accuracy of lane detection and tracking. First, datasets for performance evaluation were created using an interpolation method. Second, a learning-based approach was used to create an algorithm using the steering angle, yaw angle, and sideslip angle as inputs for the adaptive controller. Finally, simulation tests for the lane recognition method were carried out by utilising a road driving video in Melbourne, Australia, and the BDD100K dataset created by the Berkeley DeepDrive Industrial Consortium. The mean detection accuracy ranges from 97% to 99%, and the detection time ranges from 20 to 22 ms under various road conditions with our proposed algorithm. This lane detection algorithm outperformed conventional techniques in terms of accuracy and processing time, as well as efficiency in lane detection and overcoming road interferences. The proposed algorithm will contribute to advancing the lane detection and tracking of intelligent-vehicle driving assistance and help further improve intelligent vehicle driving safety.

Cities in Australia are experiencing unprecedented levels of urban overheating, which has caused a significant impact on the country’s socioeconomic environment. This article provides a comprehensive review on urban overheating, its impact on health, energy, economy, and the heat mitigation potential of a series of strategies in Australia. Existing studies show that the average urban heat island (UHI) intensity ranges from 1.0 °C to 13.0 °C. The magnitude of urban overheating phenomenon in Australia is determined by a combination of UHI effects and dualistic atmospheric circulation systems (cool sea breeze and hot desert winds). The strong relation between multiple characteristics contribute to dramatic fluctuations and high spatiotemporal variabilities in urban overheating. In addition, urban overheating contributes to serious impacts on human health, energy costs, thermal comfort, labour productivity, and social behaviour. Evidence suggest that cool materials, green roofs, vertical gardens, urban greenery, and water-based technologies can significantly alleviate the UHI effect, cool the ambient air, and create thermally balanced cities. Urban greenery, especially trees, has a high potential for mitigation. Trees and hedges can reduce the average maximum UHI by 1.0 °C. The average maximum mitigation performance values of green roofs and green walls are 0.2 °C and 0.1 °C, respectively. Reflective roofs and pavements can reduce the average maximum UHI by 0.3 °C. In dry areas, water has a high cooling potential. The average maximum cooling potential using only one technology is 0.4 °C. When two or more technologies are used at the same time, the average maximum UHI drop is 1.5 °C. The mitigation strategies identified in this article can help the governments and other stakeholders manage urban heating in the natural and built environment, and save health, energy, and economic costs.

A set of deterioration models is required to manage local government authority (LGA) pavements in a cost-effective manner; yet, most existing deterioration models have been derived for the major highways of the State Road Authority system. LGA pavements are different in terms of pavement life, the effect of the environment, loading, and expectations of performance with respect to riding quality. There is a greater emphasis on sustained light routine maintenance in LGAs. There is a need to develop models that more closely represent LGA pavements so they can be used to forecast the deterioration of the asset and to provide better guidance for rehabilitation planning. Existing pavement deterioration models, such as Highway Development Management-III (HDM-III), were examined for application to the Australian LGA pavement set. In general, such models were too complex for use in LGAs, and they also used roughness as a performance measure. Roughness is not commonly measured in LGA pavement networks. Other studies have shown that HDM-III could overestimate the deterioration of lightly loaded pavements. For this study, data on deterioration of several LGA pavements were collected and analyzed. Visual assessment data on pavement condition were captured in a “snapshot” survey of pavements of different ages. Thus, the data represent an age cross-section sample. Little or no correlation was found between any of the performance indicators and age when the full data sets were used for the analyses. Some correlation was apparent with the averaged data for each age. Even then, some of the trendlines observed indicated a performance with age, contrary to normal expectations. It appears that factors besides age have a significant influence on the behavior of LGA pavement.

Pavement management systems assist engineers in the analysis of road network pavement condition data and subsequently provide input to the planning and prioritization of road infrastructure works programs. The data also provide input to a variety of engineering and economic analyses that assist in determining the future road network condition for a range of infrastructure-funding scenarios. The fundamental calculation of future pavement condition is commonly based on a pavement age versus pavement roughness relationship. However, roughness–age relationships commonly do not take into account the pavement’s historical performance; rather, an “average” rate of roughness progression is assigned to each pavement based on its current age or current roughness measurement. Results of a research project are documented; the project involved a comprehensive evaluation of pavement performance by examining roughness progression over time with other related variables. A method of calculating and effectively displaying roughness progression and the effects of pavement maintenance was developed. The method provides a better understanding of pavement performance, which in turn led to a methodology of calculating and reporting road network performance for application to the pavement design and delivery system in Queensland, Australia. Means of using this information to improve the accuracy of roughness progression prediction were also investigated.

Industrial waste materials are increasingly being used in asphalt to improve pavement quality and reduce environmental impacts. The aim of this research was to test the pavement distress-related effects of using ground-granulated blast-furnace slag (GGBFS) as a filler in hot mix asphalt. There is potential for GGBFS to be integrated into Western Australian (WA) asphalt pavements. GGBFS was used as a replacement for the conventional hydrated lime (HL) filler used in mix designs of the Main Roads WA specifications. A control mixture (1.5% HL) was compared with three prototype mixtures containing 1.5%, 3% or 5% GGBFS instead of HL. To investigate their characteristics, we conducted wheel tracking tests, four-point bending tests, and assessments with an asphalt mixture performance tester (AMPT). The findings support the use of GGBFS in asphalt pavements. The mixture with 3% GGBFS had the best fatigue life, rutting resistance and AMPT results.

Permeable pavements have been shown to be effective stormwater treatment devices that can greatly reduce surface runoff and significantly improve the quality of stormwater runoff in urban areas. However, the potential problems with sediment clogging and consequent maintenance requirements have been identified as the main barriers to more widespread adoption of permeable pavements in urban developments. This Australian study investigates the effectiveness of using grass swales as pre-treatment devices for permeable pavements in order to reduce clogging and extend the life span of these systems. The results of simulated runoff experiments demonstrated that between 50 and 75% of the total suspended sediment (TSS) was removed within the first 10 m of the swale length. This suggests swales of this length could potentially increase the effective life of permeable pavement systems by reducing clogging, and therefore maintenance. Nutrient removal was also tested in the study and the results indicated the tested swales were of limited effectiveness in the removal of these pollutants. However, in real runoff situations, reduction of TSS will have a direct influence on removing nutrients because a significant proportion of nutrients (and other pollutants) are attached to the sediments.

Purpose In order to fully understand the properties of porous asphalt, investigation should be conducted from different point of views. This is from the fact that porous asphalt mixture designed with the same aggregate gradation and air void content can give different infiltration rate due to the different formation of the internal structure. Therefore, the purpose of this paper is to investigate the micro-structural properties and functional performance of porous asphalt simultaneously. Design/methodology/approach The aim is to develop imaging techniques to process and analyze the internal structure of porous asphalt mixture. A few parameters were established to analyze the air void properties and aggregate interlock within the gyratory compacted samples captured using a non-destructive scanning technique of X-ray computed tomography (CT) throughout the samples. The results were then compared with the functional performance in terms of permeability. Four aggregate gradations used in different countries, i.e. Malaysia, Australia, the USA and Singapore. The samples were tested for resilient modulus and permeability. Quantitative analysis of the microstructure was used to establish the relationships between the air void properties and aggregate interlock and the resilient modulus and permeability. Findings Based on the results, it was found that the micro-structural properties investigated have successfully described the internal structure formation and they reflect the results of resilient modulus and permeability. In addition, the imaging technique which includes the image processing and image analysis for internal structure quantification seems to be very useful and perform well with the X-ray CT images based on the reliable results obtained from the analysis. Research limitations/implications In this study, attention was limited to the study of internal structure of porous asphalt samples prepared in the laboratory using X-ray CT but can also be used to assess the quality of finished asphalt pavements by taking core samples for quantitative and qualitative analysis. The use of CT for material characterization presents a lot of possibilities in the future of asphalt concrete mix design. Originality/value Based on the validation process which includes comparisons between the values obtained from the image analysis and those from the performance test and it was found that the developed procedure satisfactorily assesses the air voids distribution and the aggregate interlock for this reason, it can be used.

The benefits of using permeable interlocking concrete pavement systems (PICPs) have not translated into widespread adoption in Australia, where their uptake has been slow. This paper communicates the actual performance of PICPs installed in the field by providing evidence of their long-term efficiency. There are currently no Australian standards for design, specification and installation of PICPs. In this study, field measurements were conducted to determine the infiltration capacity of PICPs in Sydney and Wollongong, New South Wales, applying the single ring infiltrometer test (SRIT) and the stormwater infiltration field test (SWIFT). A strong correlation was found between the results of the two tests in a previous study, which was verified in this study. The long-term performance of PICPs is demonstrated by their high infiltration rates (ranging from 125 mm/h to 25,000 mm/h) measured in this study at field sites under a diverse range of conditions. The influences of conditions such as age of installation, slope and tree cover on infiltration rates were explored.

The Mechanistic empirical pavement design method for flexible pavements is based on modelling certain modes of failures for different pavement materials. In the Australian and New Zealand guidelines, the mechanistic empirical pavement design is based on modelling fatigue and permanent deformation as the two major modes of failures. The Austroads guidelines use the Shell fatigue performance transfer function to model the fatigue behaviour of asphalt mixes. In this research, the fatigue behaviour of different mixes AC10, AC14 and AC20 with different types of binders 80/100 and 60/70 was thoroughly investigated. The Shell model significantly underestimated the measured fatigue life for all mixes. A wide range of properties of the examined mixes was considered; percent of air voids ranges from 1.2% to 11.4%, binder content (at optimum, ± 0.5 from optimum), and the flexural modulus ranges from 1600 to 4576 MPa. A new fatigue model was developed at the University of Canterbury. The Canterbury model was based on the bending beam fatigue results of 78 beams tested at constant strain mode at different strain levels range from 300 to 600 microstrains. The new model provides a much better matching to the measured data with no observed bias and it accounts for percentage of air voids in the total mix and the effective binder content instead of the total binder content that is currently included in the Shell Model.

The determination of appropriate pavement thickness using laboratory determined parameters is one of the key issues facing the road manager. Five different types of asphalt mixes were produced in laboratory to modify pavement performance mixture. The main objective of this study is to evaluate the characterization methods for fatigue performance of asphalt mixes to Western Australia road. In this study, laboratory test for indirect tensile modulus, dynamic creep, wheel tracking and aggregate gradation tests were taken to analyze each asphalt mixtures for a design traffic road. The results and analysis showed that AC20-75 asphalt mix blow is the most effective and efficient in pavement performance than the other asphalt mixes. AC14-75 was the second in rank to strengthen and durability of asphalt pavement. All asphalt mixes in this study can be used to strength and stable the overall stiffness of pavement, and modification rank can be described as AC20-75 Blow > AC14-75 Blow > AC14-50 Blow > AC7-50 Blow > SMA7-50 Blow in this research.

The use of deep strength asphalt materials characterization to construct and restore the heavily urban roads where damage has been induced is rapidly grown in Western Australia. Five different types of asphalt mixes were produced in laboratory to modify pavement performance mixture. The main role of this research is to evaluate the pavement materials characterization for Western Australia road. In this study, laboratory test for tensile strength, resilient modulus, wheel tracking, binder contents, Marshall Compaction, and air voids contents test were taken to analyze each asphalt mixtures. The results indicated that AC20-75 and AC14-75 asphalt mixes blow were in a good pavement performance as compared to other asphalt mixes. For a mix design purposed, all the asphalt mixes that are used in this study can strength and stable the stiffness of pavement that is notable, and the modification effect rank can be described as AC20-75 Blow > AC14-75 Blow > AC14-50 Blow > AC7-50 Blow > SMA7-50 Blow in this research.

Bitumen emulsion stabilisation of locally available Tamala Limestone was widely used by State and Local Governments from the mid-1960s through the late-1990s, however its use has declined in recent years. This paper aims to substantiate its benefits as a viable alternative material for use on heavily trafficked roads. The benefits provided through stabilisation of crushed limestone with bitumen emulsion include improved workability, reduced ravelling under construction traffic, lower moisture susceptibility and enhanced mechanical properties. Case studies are presented that show that satisfactory performance has been observed where Bitumen Stabilised Limestone (BSL) is used as a basecourse under heavily trafficked roads. The paper provides a construction methodology and discusses barriers and future opportunities. Two structural design approaches are presented for the use of BSL under sprayed seals and thin asphalt surfacings.

The 6.4 km long Port Reitz/Moi International Access Road project constructed under the design and build procurement method with an inherent risk of poor quality. A post-construction pavement performance evaluation is thus critical to evaluate the extent to which poor quality occurred. The International Roughness Index was measured using the Hawkeye-2000 Digital Laser Profiler with Pavement Logging Video Camera mounted on a calibrated vehicle and data was analysed using the Hawkeye Processing Toolkit Version 5.0.45, while the road roughness Rating was based on the Australian Road Research Board. The video record was analysed in blocks of equal lengths of 100 m for observation and assessment of the surface defects. The level of defects observed graded together with the IRI measurements gave the Present serviceability Index. Pavement Serviceability Index (PSI) was computed in compliance with ASTM 6433. The falling weight deflectometer equipment meeting the requirement of ASTM D4694 - 09 and ASTM D4695 used to measure pavement deflections under known load simulated the behaviour of the as-built pavement under loading, thus giving the pavement strength and the expected pavement life span. The deflection measurements were conducted on all lanes at intervals of approximately 100 m. The raw deflections (rd) data were converted to normalised deflection (nd) to simulate a standard pressure of 707 KPa from a dual-wheel assembly of 10-ton (100-kN). Back calculation of deflection data done using Rosy Design Software determined the layer strength and residual life. The analysis indicates that the road has residual life ranging from 20-6 years compared to 20-year design life consistent with the assumptions by Ogunsanmi (2019) that Design and Build contracts have an inherent risk of poor quality. In addition to incorporation and monitoring of quality through the design, construction and maintenance stages of the project, identification, evaluation, management, and monitoring of the inherent project risks are recommended for Design and Built Contracts in road projects.

This laboratory-based study investigated the performance characteristics of wet process crumb rubber modified asphalt (CRMA) with crumb rubber proportions between 0% and 20% by mass of the binder. This was to assess the viability of CRMA for use in countries where CRMA is not widely utilized as Australia and Thailand and primarily involved the resilient and dynamic modulus characteristics, which indicated that CRMA pavement has both positive and negative attributes. The results show that CRMA characterizes a reduced stiffness for high frequency loading, but with a greater elastic range.

ABSTRACT A vast amount of construction and demolition (C&D) wastes are generated in Western Australia (WA) of which a major portion goes to landfills. The diversion of C&D waste from landfills would be the single most significant opportunity for WA to improve its recovery performance. C&D waste materials have already been investigated for their appropriateness and use in pavement and concrete. This work is the continuation of the authors’ previous work involving further experimental tests to prove the structural suitability of a building’s structural member (i.e., beam) made of recycled aggregates and industrial by-products. The concrete mixes considered in this study are 100NA+100 OPC (Control), 100RA+100OPC, 50RA+50NA+90OPC+10SF and 50RA+50NA+60OPC+30FA+10SF. The Reinforced Concrete (RC) beam made of 50RA+50NA+60OPC+30FA+10SF concrete mix was found to be the only eco-efficient option. This option has reduced the level of environmental impacts in a cost-competitive manner. The use of this eco-efficient option could also provide new employment opportunities and significant improvements in terms of land and energy resources conservation and bio-diversity enhancement.

Slags and rubber from end-of-life tires represent a liability to the steel and tire industry, causing economic and environmental problems that are difficult to manage. Transport infrastructures can use these industrial by-products instead of extracting natural raw materials, but the adequate mechanical performance of the materials needs to be assured. This paper addresses the mechanical behaviour of slag–rubber mixtures in the laboratory with CBR, monotonic and cyclic triaxial tests. In addition, light falling weight deflectometer tests were also performed in a physical model. The results were analysed to meet technical specifications from Brazil, Portugal and Australia using railway sub-ballast layers, capping layers or road pavement layers as the base and sub-base to identify the applicability range of slag–rubber mixtures for transport infrastructures. Concerning the analysed parameters, it was demonstrated that slag–rubber mixtures can show resilient behaviour and strength adequate for the support layers of transport infrastructures provided that the rubber content is below 5% in weight and that the slag is milled to comply with the grain size distribution ranges available in the technical specifications of the cited countries.

The importance of specifying proper aggregate grading for achieving satisfactory performance in pavement applications has long been recognized. To improve the specifications for superior performance, there is a need to understand how differences in aggregate gradations within the acceptable limits may affect unbound aggregate base behavior. The effects of gradation on strength, modulus, and deformation characteristics of high-quality crushed rock base materials are described here. Two crushed rock types commonly used in constructing heavy-duty granular base layers in the State of Victoria, Australia, with three different gradations each were used in this study. The gradations used represent the lower, medium, and upper gradation limits for heavy-duty base materials specified by the State of Victoria’s road agency (VicRoads). Modified compaction tests were conducted first to determine the moisture-density relationship of all mixes. Further, California bearing ratio (CBR), unconfined compressive strength (UCS), and repeated load triaxial (RLT) tests were then performed to study the effects of different gradations on strength, resilient modulus (MR), and deformation resistance. Further, permanent deformation and MR results were modeled using two popular models for each to explain the effect of gradation on the mixtures’ characteristics. The results indicate that the gradation that provides the best characteristics varies depending on the type of material used. For the materials tested here, coarse and medium gradations provide the best mixture characteristics in relation to CBR, MR, and permanent deformation. Fine gradation mixtures of these materials have lower values of these measures but are still considered acceptable considering relevant specification for the intended application.

The dynamic modulus of the asphalt mixtures is an important factor in designing or analyzing an asphalt concrete pavement, but it is expensive and time consuming to measure. Therefore, it is important to develop a model to predict this value. In this regard, the Hirsch model is a popular model, however, it is developed based on a range of U.S. asphalt mixtures and standards. Therefore, it is not certain that it can be used for asphalt mixtures based on materials and codes other than U.S. This article investigated whether this model performs satisfactorily with two typical asphalt mixtures in Western Australia (WA) containing 0, 10, 20, and 30% of recycled asphalt pavement. To do so, cylindrical samples were made with materials and locally established standards in Western Australia and then tested in Asphalt Mixture Performance Tester (AMPT) machine to acquire their dynamic modulus and phase angle values in different loading frequencies (0.01 to 10 Hz) and temperatures (4 to 40°C). Meanwhile, the results are estimated by the Hirsch model using some properties of the mixture and binder. The properties of the binder in different test conditions are obtained using a dynamic shear rheometer. The comparison of the results showed that the dynamic modulus underestimation or overestimation error can reach to 50 and 280% respectively. Generally, this model did not perform well in this study.

In the new AASHTO Mechanistic-Empirical Pavement Design Guide (MEPDG), the dynamic modulus |E*| test has been selected to assess the performance of asphalt concretes. The type of test, which relates asphalt mixtures modulus to temperature and time rate of loading, is never used in Western Australia. This paper presents a study on the dynamic modulus of typical Western Australia asphalt mixtures. Five mixtures with 10mm nominal sizes and two types of bitumen classes, i.e. C170 (Pen 60/80) and C320 (Pen 40/60) comply with Main Road Western Australia (MRWA) Specification were used in the research. Mixing and compacting process were carried out according to Austroads methods. The specimens were compacted using a gyratory compactor to achieve 5±0.5% target air void. Testing was performed at four temperatures (4, 20, 40 and 55OC) and six frequencies (25, 10, 5, 1, 0.5, 0.1 and 0.05 Hz). Dynamic modulus and phase angle master curves were generated from the results. The master curves were compared to the curves from Witczak’s predictive equation. From this preliminary study, it was found that the measured values correlated well with the predictive equation except at high temperatures or low frequencies.

IntroductionThe walking tour is an enduring feature of cities. Fuelled by a desire to learn more about the hidden and unknown spaces of the city, the walking tour has moved beyond its historical role as tourist attraction to play a key role in the transformation of urban space through gentrification. Conversely, the walking tour has a counter-history as part of a critical urban praxis. This article reflects on historical examples, as well as our own experience of conducting Field Trip, a critical geographical walking tour through an industrial precinct in Marrickville, a suburb of Sydney that is set to undergo rapid change as a result of high-rise residential apartment construction (Gibson et al.). This precinct, known as Carrington Road, is located on the unceded land of the Cadigal and Wangal people of the Eora nation who call the area Bulanaming.Drawing on a long history of philosophical walking, many contemporary writers (Solnit; Gros; Bendiner-Viani) have described walking as a practice that can open different ways of thinking, observing and being in the world. Some have focused on the value of walking to the study of place (Hall; Philips; Heddon), and have underscored its relationship to established research methods, such as sensory ethnography (Springgay and Truman). The work of Michel de Certeau pays particular attention to the relationship between walking and the city. In particular, the concepts of tactics and strategy have been applied in a variety of ways across cultural studies, cultural geography, and urban studies (Morris). In line with de Certeau’s thinking, we view walking as an example of a tactic – a routine and often unconscious practice that can become a form of creative resistance.In this sense, walking can be a way to engage in and design the city by opposing its structures, or strategies. For example, walking in a city such as Sydney that is designed for cars requires choosing alternative paths, redirecting flows of people and traffic, and creating custom shortcuts. Choosing pedestrianism in Sydney can certainly feel like a form of resistance, and we make the argument that Field Trip – and walking tours more generally – can be a way of doing this collectively, firstly by moving in opposite directions, and secondly, at incongruent speeds to those for whom the scale and style of strategic urban development is inevitable. How such tactical walking relates to the design of cities, however, is less clear. Walking is a generally described in the literature as an individual act, while the design of cities is, at its best participatory, and always involving multiple stakeholders. This reveals a tension between the practice of walking as a détournement or appropriation of urban space, and its relationship to existing built form. Field Trip, as an example of collective walking, is one such appropriation of urban space – one designed to lead to more democratic decision making around the planning and design of cities. Given the anti-democratic, “post-political” nature of contemporary “consultation” processes, this is a seemingly huge task (Legacy et al.; Ruming). We make the argument that Field Trip – and walking tours more generally – can be a form of collective resistance to top-down urban planning.By using an open-source wiki in combination with the Internet Archive, Field Trip also seeks to collectively document and make public the local knowledge generated by walking at the frontier of gentrification. We discuss these digital choices as oppositional practice, and consider the idea of tactical media (Lovink and Garcia; Raley) in order to connect knowledge sharing with the practice of walking.This article is structured in four parts. Firstly, we provide a historical introduction to the relationship between walking tours and gentrification of global cities. Secondly, we examine the significance of walking tours in Sydney and then specifically within Marrickville. Thirdly, we discuss the Field Trip project as a citizen-led walking tour and, finally, elaborate on its role as tactical media project and offer some conclusions.The Walking Tour and Gentrification From the outset, people have been walking the city in their own ways and creating their own systems of navigation, often in spite of the plans of officialdom. The rapid expansion of cities following the Industrial Revolution led to the emergence of “imaginative geographies”, where mediated representations of different urban conditions became a stand-in for lived experience (Steinbrink 219). The urban walking tour as mediated political tactic was utilised as far back as Victorian England, for reasons including the celebration of public works like the sewer system (Garrett), and the “othering” of the working class through upper- and middle-class “slum tourism” in London’s East End (Steinbrink 220). The influence of the Situationist theory of dérive has been immense upon those interested in walking the city, and we borrow from the dérive a desire to report on the under-reported spaces of the city, and to articulate alternative voices within the city in this project. It should be noted, however, that as Field Trip was developed for general public participation, and was organised with institutional support, some aspects of the dérive – particularly its disregard for formal structure – were unable to be incorporated into the project. Our responsibility to the participants of Field Trip, moreover, required the imposition of structure and timetable upon the walk. However, our individual and collective preparation for Field Trip, as well as our collective understanding of the area to be examined, has been heavily informed by psychogeographic methods that focus on quotidian and informal urban practices (Crosby and Searle; Iveson et al).In post-war American cities, walking tours were utilised in the service of gentrification. Many tours were organised by real estate agents with the express purpose of selling devalorised inner-city real estate to urban “pioneers” for renovation, including in Boston’s South End (Tissot) and Brooklyn’s Park Slope, among others (Lees et al 25). These tours focused on a symbolic revalorisation of “slum neighbourhoods” through a focus on “high culture”, with architectural and design heritage featuring prominently. At the same time, urban socio-economic and cultural issues – poverty, homelessness, income disparity, displacement – were downplayed or overlooked. These tours contributed to a climate in which property speculation and displacement through gentrification practices were normalised. To this day, “ghetto tours” operate in minority neighbourhoods in Brooklyn, serving as a beachhead for gentrification.Elsewhere in the world, walking tours are often voyeuristic, featuring “locals” guiding well-meaning tourists through the neighbourhoods of some of the world’s most impoverished communities. Examples include the long runningKlong Toei Private Tour, through “Bangkok’s oldest and largest slum”, or the now-ceased Jakarta Hidden Tours, which took tourists to the riverbanks of Jakarta to see the city’s poorest before they were displaced by gentrification.More recently, all over the world activists have engaged in walking tours to provide their own perspective on urban change, attempting to direct the gentrifier’s gaze inward. Whilst the most confrontational of these might be the Yuppie Gazing Tour of Vancouver’s historically marginalised Downtown Eastside, other tours have highlighted the deleterious effects of gentrification in Williamsburg, San Francisco, Oakland, and Surabaya, among others. In smaller towns, walking tours have been utilised to highlight the erasure of marginalised scenes and subcultures, including underground creative spaces, migrant enclaves, alternative and queer spaces. Walking Sydney, Walking Marrickville In many cities, there are now both walking tours that intend to scaffold urban renewal, and those that resist gentrification with alternative narratives. There are also some that unwittingly do both simultaneously. Marrickville is a historically working-class and migrant suburb with sizeable populations of Greek and Vietnamese migrants (Graham and Connell), as well as a strong history of manufacturing (Castles et al.), which has been undergoing gentrification for some time, with the arts playing an often contradictory role in its transformation (Gibson and Homan). More recently, as the suburb experiences rampant, financialised property development driven by global flows of capital, property developers have organised their own self-guided walking tours, deployed to facilitate the familiarisation of potential purchasers of dwellings with local amenities and ‘character’ in precincts where redevelopment is set to occur. Mirvac, Marrickville’s most active developer, has designed its own self-guided walking tour Hit the Marrickville Pavement to “explore what’s on offer” and “chat to locals”: just 7km from the CBD, Marrickville is fast becoming one of Sydney’s most iconic suburbs – a melting pot of cuisines, creative arts and characters founded on a rich multicultural heritage.The perfect introduction, this self-guided walking tour explores Marrickville’s historical architecture at a leisurely pace, finishing up at the pub.So, strap on your walking shoes; you're in for a treat.Other walking tours in the area seek to highlight political, ecological, and architectural dimension of Marrickville. For example, Marrickville Maps: Tropical Imaginaries of Abundance provides a series of plant-led walks in the suburb; The Warren Walk is a tour organised by local Australian Labor Party MP Anthony Albanese highlighting “the influence of early settlers such as the Schwebel family on the area’s history” whilst presenting a “political snapshot” of ALP history in the area. The Australian Ugliness, in contrast, was a walking tour organised by Thomas Lee in 2016 that offered an insight into the relationships between the visual amenity of the streetscape, aesthetic judgments of an ambiguous nature, and the discursive and archival potentialities afforded by camera-equipped smartphones and photo-sharing services like Instagram. Figure 1: Thomas Lee points out canals under the street of Marrickville during The Australian Ugliness, 2016.Sydney is a city adept at erasing its past through poorly designed mega-projects like freeways and office towers, and memorialisation of lost landscapes has tended towards the literary (Berry; Mudie). Resistance to redevelopment, however, has often taken the form of spectacular public intervention, in which public knowledge sharing was a key goal. The Green Bans of the 1970s were partially spurred by redevelopment plans for places like the Rocks and Woolloomooloo (Cook; Iveson), while the remaking of Sydney around the 2000 Olympics led to anti-gentrification actions such as SquatSpace and the Tour of Beauty, an “aesthetic activist” tour of sites in the suburbs of Redfern and Waterloo threatened with “revitalisation.” Figure 2: "Tour of Beauty", Redfern-Waterloo 2016. What marks the Tour of Beauty as significant in this context is the participatory nature of knowledge production: participants in the tours were addressed by representatives of the local community – the Aboriginal Housing Company, the local Indigenous Women’s Centre, REDWatch activist group, architects, designers and more. Each speaker presented their perspective on the rapidly gentrifying suburb, demonstrating how urban space is made an remade through processes of contestation. This differentiation is particularly relevant when considering the basis for Sydney-centric walking tours. Mirvac’s self-guided tour focuses on the easy-to-see historical “high culture” of Marrickville, and encourages participants to “chat to locals” at the pub. It is a highly filtered approach that does not consider broader relations of class, race and gender that constitute Marrickville. A more intense exploration of the social fabric of the city – providing a glimpse of the hidden or unknown spaces – uncovers the layers of social, cultural, and economic history that produce urban space, and fosters a deeper engagement with questions of urban socio-spatial justice.Solnit argues that walking can allow us to encounter “new thoughts and possibilities.” To walk, she writes, is to take a “subversive detour… the scenic route through a half-abandoned landscape of ideas and experiences” (13). In this way, tactical activist walking tours aim to make visible what cannot be seen, in a way that considers the polysemic nature of place, and in doing so, they make visible the hidden relations of power that produce the contemporary city. In contrast, developer-led walking tours are singularly focussed, seeking to attract inflows of capital to neighbourhoods undergoing “renewal.” These tours encourage participants to adopt the position of urban voyeur, whilst activist-led walking tours encourage collaboration and participation in urban struggles to protect and preserve the contested spaces of the city. It is in this context that we sought to devise our own walking tour – Field Trip – to encourage active participation in issues of urban renewal.In organising this walking tour, however, we acknowledge our own entanglements within processes of gentrification. As designers, musicians, writers, academics, researchers, venue managers, artists, and activists, in organising Field Trip, we could easily be identified as “creatives”, implicated in Marrickville’s ongoing transformation. All of us have ongoing and deep-rooted connections to various Sydney subcultures – the same subcultures so routinely splashed across developer advertising material. This project was borne out of Frontyard – a community not-just-art space, and has been supported by the local Inner West Council. As such, Field Trip cannot be divorced from the highly contentious processes of redevelopment and gentrification that are always simmering in the background of discussions about Marrickville. We hope, however, that in this project we have started to highlight alternative voices in those redevelopment processes – and that this may contribute towards a “method of equality” for an ongoing democratisation of those processes (Davidson and Iveson).Field Trip: Urban Geographical Enquiry as Activism Given this context, Field Trip was designed as a public knowledge project that would connect local residents, workers, researchers, and decision-makers to share their experiences living and working in various parts of Sydney that are undergoing rapid change. The site of our project – Carrington Road, Marrickville in Sydney’s inner-west – has been earmarked for major redevelopment in coming years and is quickly becoming a flashpoint for the debates that permeate throughout the whole of Sydney: housing affordability, employment accessibility, gentrification and displacement. To date, public engagement and consultation regarding proposed development at Carrington Road has been limited. A major landholder in the area has engaged a consultancy firm to establish a community reference group (CRG) the help guide the project. The CRG arose after public outcry at an original $1.3 billion proposal to build 2,616 units in twenty towers of up to 105m in height (up to thirty-five storeys) in a predominantly low-rise residential suburb. Save Marrickville, a community group created in response to the proposal, has representatives on this reference group, and has endeavoured to make this process public. Ruming (181) has described these forms of consultation as “post-political,” stating thatin a universe of consensual decision-making among diverse interests, spaces for democratic contest and antagonistic politics are downplayed and technocratic policy development is deployed to support market and development outcomes.Given the notable deficit of spaces for democratic contest, Field Trip was devised as a way to reframe the debate outside of State- and developer-led consultation regimes that guide participants towards accepting the supposed inevitability of redevelopment. We invited a number of people affected by the proposed plans to speak during the walking tour at a location of their choosing, to discuss the work they do, the effect that redevelopment would have on their work, and their hopes and plans for the future. The walking tour was advertised publicly and the talks were recorded, edited and released as freely available podcasts. The proposed redevelopment of Carrington Road provided us with a unique opportunity to develop and operate our own walking tour. The linear street created an obvious “circuit” to the tour – up one side of the road, and down the other. We selected speakers based on pre-existing relationships, some formed during prior rounds of research (Gibson et al.). Speakers included a local Aboriginal elder, a representative from the Marrickville Historical Society, two workers (who also gave tours of their workplaces), the Lead Heritage Adviser at Sydney Water, who gave us a tour of the Carrington Road pumping station, and a representative from the Save Marrickville residents’ group. Whilst this provided a number of perspectives on the day, regrettably some groups were unrepresented, most notably the perspective of migrant groups who have a long-standing association with industrial precincts in Marrickville. It is hoped that further community input and collaboration in future iterations of Field Trip will address these issues of representation in community-led walking tours.A number of new understandings became apparent during the walking tour. For instance, the heritage-listed Carrington Road sewage pumping station, which is of “historic and aesthetic significance”, is unable to cope with the proposed level of residential development. According to Philip Bennett, Lead Heritage Adviser at Sydney Water, the best way to maintain this piece of heritage infrastructure is to keep it running. While this issue had been discussed in private meetings between Sydney Water and the developer, there is no formal mechanism to make this expert knowledge public or accessible. Similarly, through the Acknowledgement of Country for Field Trip, undertaken by Donna Ingram, Cultural Representative and a member of the Metropolitan Local Aboriginal Land Council, it became clear that the local Indigenous community had not been consulted in the development proposals for Carrington Road. This information, while not necessary secret, had also not been made public. Finally, the inclusion of knowledgeable local workers whose businesses are located on Carrington Road provided an insight into the “everyday.” They talked of community and collaboration, of site-specificity, the importance of clustering within their niche industries, and their fears for of displacement should redevelopment proceed.Via a community-led, participatory walking tour like Field Trip, threads of knowledge and new information are uncovered. These help create new spatial stories and readings of the landscape, broadening the scope of possibility for democratic participation in cities. Figure 3: Donna Ingram at Field Trip 2018.Tactical Walking, Tactical Media Stories connected to walking provide an opportunity for people to read the landscape differently (Mitchell). One of the goals of Field Trip was to begin a public knowledge exchange about Carrington Road so that spatial stories could be shared, and new readings of urban development could spread beyond the confines of the self-contained tour. Once shared, this knowledge becomes a story, and once remixed into existing stories and integrated into the way we understand the neighbourhood, a collective spatial practice is generated. “Every story is a travel story – a spatial practice”, says de Certeau in “Spatial Stories”. “In reality, they organise walks” (72). As well as taking a tactical approach to walking, we took a tactical approach to the mediation of the knowledge, by recording and broadcasting the voices on the walk and feeding information to a publicly accessible wiki. The term “tactical media” is an extension of de Certeau’s concept of tactics. David Garcia and Geert Lovink applied de Certeau’s concept of tactics to the field of media activism in their manifesto of tactical media, identifying a class of producers who amplify temporary reversals in the flow of power by exploiting the spaces, channels and platforms necessary for their practices. Tactical media has been used since the late nineties to help explain a range of open-source practices that appropriate technological tools for political purposes. While pointing out the many material distinctions between different types of tactical media projects within the arts, Rita Raley describes them as “forms of critical intervention, dissent and resistance” (6). The term has also been adopted by media activists engaged in a range of practices all over the world, including the Tactical Technology Collective. For Field Trip, tactical media is a way of creating representations that help navigate neighbourhoods as well as alternative political processes that shape them. In this sense, tactical representations do not “offer the omniscient point of view we associate with Cartesian cartographic practice” (Raley 2). Rather these representations are politically subjective systems of navigation that make visible hidden information and connect people to the decisions affecting their lives. Conclusion We have shown that the walking tour can be a tourist attraction, a catalyst to the transformation of urban space through gentrification, and an activist intervention into processes of urban renewal that exclude people and alternative ways of being in the city. This article presents practice-led research through the design of Field Trip. By walking collectively, we have focused on tactical ways of opening up participation in the future of neighbourhoods, and more broadly in designing the city. By sharing knowledge publicly, through this article and other means such as an online wiki, we advocate for a city that is open to multimodal readings, makes space for sharing, and is owned by those who live in it. References Armstrong, Helen. “Post-Urban/Suburban Landscapes: Design and Planning the Centre, Edge and In-Between.” After Sprawl: Post Suburban Sydney: E-Proceedings of Post-Suburban Sydney: The City in Transformation Conference, 22-23 November 2005, Riverside Theatres, Parramatta, Sydney. 2006.Bendiner-Viani, Gabrielle. “Walking, Emotion, and Dwelling.” Space and Culture 8.4 (2005): 459-71. Berry, Vanessa. Mirror Sydney. Sydney: Giramondo, 2017.Castles, Stephen, Jock Collins, Katherine Gibson, David Tait, and Caroline Alorsco. “The Global Milkbar and the Local Sweatshop: Ethnic Small Business and the Economic Restructuring of Sydney.” Centre for Multicultural Studies, University of Wollongong, Working Paper 2 (1991).Crosby, Alexandra, and Kirsten Seale. “Counting on Carrington Road: Street Numbers as Metonyms of the Urban.” Visual Communication 17.4 (2018): 1-18. Crosby, Alexandra. “Marrickville Maps: Tropical Imaginaries of Abundance.” Mapping Edges, 2018. 25 Jun. 2018 <http://www.mappingedges.org/news/marrickville-maps-tropical-imaginaries-abundance/>.Cook, Nicole. “Performing Housing Affordability: The Case of Sydney’s Green Bans.” Housing and Home Unbound: Intersections in Economics, Environment and Politics in Australia. Eds. Nicole Cook, Aidan Davidson, and Louise Crabtree. London: Routledge, 2016. 190-203.Davidson, Mark, and Kurt Iveson. “Recovering the Politics of the City: From the ‘Post-Political City’ to a ‘Method of Equality’ for Critical Urban Geography.” Progress in Human Geography 39.5 (2015): 543-59. De Certeau, Michel. “Spatial Stories.” What Is Architecture? Ed. Andrew Ballantyne. London: Routledge, 2002. 72-87.Dobson, Stephen. “Sustaining Place through Community Walking Initiatives.” Journal of Cultural Heritage Management and Sustainable Development 1.2 (2011): 109-21. Garrett, Bradley. “Picturing Urban Subterranea: Embodied Aesthetics of London’s Sewers.” Environment and Planning A: Economy and Space 48.10 (2016): 1948-66. Gibson, Chris, and Shane Homan. “Urban Redevelopment, Live Music, and Public Space: Cultural Performance and the Re-Making of Marrickville.” International Journal of Cultural Policy 10.1 (2004): 67-84. Gibson, Chris, Carl Grodach, Craig Lyons, Alexandra Crosby, and Chris Brennan-Horley. 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Heddon, Dierdre, and Misha Myers. “Stories from the Walking Library.” Cultural Geographies 21.4 (2014): 1-17. Iveson, Kurt. “Building a City for ‘The People’: The Politics of Alliance-Building in the Sydney Green Ban Movement.” Antipode 46.4 (2014): 992-1013. Iveson, Kurt, Craig Lyons, Stephanie Clark, and Sara Weir. “The Informal Australian City.” Australian Geographer (2018): 1-17. Jones, Phil, and James Evans. “Rescue Geography: Place Making, Affect and Regeneration.” Urban Studies 49.11 (2011): 2315-30. Lees, Loretta, Tom Slater, and Elvin Wyly. Gentrification. New York: Routledge, 2008.Legacy, Crystal, Nicole Cook, Dallas Rogers, and Kristian Ruming. “Planning the Post‐Political City: Exploring Public Participation in the Contemporary Australian City.” Geographical Research 56.2 (2018): 176-80. Lovink, Geert, and David Garcia. “The ABC of Tactical Media.” Nettime, 1997. 3 Oct. 2018 <http://www.nettime.org/Lists-Archives/nettime-l-9705/msg00096.html>.Mitchell, Don. “New Axioms for Reading the Landscape: Paying Attention to Political Economy and Social Justice.” Political Economies of Landscape Change. Eds. James L. Wescoat Jr. and Douglas M. Johnson. Dordrecht: Springer, 2008. 29-50.Morris, Brian. “What We Talk about When We Talk about ‘Walking in the City.’” Cultural Studies 18.5 (2004): 675-97. Mudie, Ella. “Unbuilding the City: Writing Demolition.” M/C Journal 20.2 (2017).Phillips, Andrea. “Cultural Geographies in Practice: Walking and Looking.” Cultural Geographies 12.4 (2005): 507-13. Pink, Sarah. “An Urban Tour: The Sensory Sociality of Ethnographic Place-Making.”Ethnography 9.2 (2008): 175-96. Pink, Sarah, Phil Hubbard, Maggie O’Neill, and Alan Radley. “Walking across Disciplines: From Ethnography to Arts Practice.” Visual Studies 25.1 (2010): 1-7. Quiggin, John. “Blogs, Wikis and Creative Innovation.” International Journal of Cultural Studies 9.4 (2006): 481-96. Raley, Rita. Tactical Media. Vol. 28. Minneapolis: U of Minnesota P, 2009.Ruming, Kristian. “Post-Political Planning and Community Opposition: Asserting and Challenging Consensus in Planning Urban Regeneration in Newcastle, New South Wales.” Geographical Research 56.2 (2018): 181-95. Solnit, Rebecca. Wanderlust: A History of Walking. New York: Penguin Books, 2001.Steinbrink, Malte. “‘We Did the Slum!’ – Urban Poverty Tourism in Historical Perspective.” Tourism Geographies 14.2 (2012): 213-34. Tissot, Sylvie. Good Neighbours: Gentrifying Diversity in Boston’s South End. London: Verso, 2015.

Let me walk. Let me go at my own pace. Let me feel life as it moves through me and around me. Give me drama. Give me unexpected curvilinear corners. Give me unsettling churches and beautiful storefronts and parks I can lie down in. The city turns you on, gets you going, moving, thinking, wanting, engaging (Elkin 37, emphasis our own). Walking Is ThinkingAs feet pound the pavement, synaptic movement follows. To clear the head, one must get up and walk.In her 2016 book Flaneuse: Women Walk the City in Paris, New York, Tokyo, Venice and London, Lauren Elkin traces the figure of the walking woman— often herself—through literary and artistic movements and the metropolis. She explores the act of flânerie, of wandering the city, as performed by George Sand, Virginia Woolf and Martha Gellhorn, amongst other peripatetic female thinkers. For Elkin, walking is at once an act of protest, of pleasure, a way to navigate personal pain, but also a way of thinking. She writes, “sometimes I walk because I have things on my mind, and walking helps me sort them out” (21).In “On the Rhythms of Walking and Seeing: Two Walks across the Page”, Evija Trofimova and Sophie Nicholls take this further, and amble towards one another thoughtfully, but from other sides of the globe. They address Elkins’s “sorting out” by coming together, not in the physical, but on the page. They address the frustration that can occur before the words appear on the page, when we as writers are “stuck”—and how moving away from the static confines of the office, away from the desk, and going for a walk, makes the work much richer when we return. Yet walking is more than that again: Trofimova and Nicholls also demonstrate how companionable the act of walking is, and how co-writing can achieve this simpatico too. Their essay is a conversation, a walk together, a work together. It is rhythmic and roaming, and like Elkin, references thinkers who have relied on the ramble to relieve the block.Walking Is WritingWhile we were editing this issue, Rebecca Solnit’s book Wanderlust: A History of Walking appeared on the reference list of many articles we received. Wanderlust, first published in 2001, has become a contemporary classic—part of a “Walking Canon”, if you will—for its exhaustive study of walking and its artistic, philosophical, and political histories. Like Trofimova and Nicholls, Daniel Juckes also engages with Solnit’s work in his article “Walking as Practice and Prose as Path Making: How Life Writing and Journey can Intersect.” Reflecting on W. G. Sebald, Marcel Proust, and the family memoir he was writing, Juckes refers to Solnit’s discussion of the connection between place, path, and memory. He writes that “if a person is searching for some kind of possible-impossible grounding in the past, then walking pace is the pace at which to achieve that sensation (both in the world and on the page).” Like in dreams, this realm of im/possibility can occur through writing, but is also fostered through walking. As Solnit reminds us, “exploring the world is one of the best ways of exploring the mind, and walking travels both terrains” (13). In Juckes’s work we see how walking and memory can be intimately connected; how both, as Juckes puts it, are bound up in “the making of connections between present and past,” as we tread across old associations and they are made anew.Walking Is PrivilegeAs we discuss the pedestrian benefits of walking, it would be remiss to fail to acknowledge those with restricted mobility due to a disability or illness. Ableism permeates the world we live in. As such, an important aspect of this issue is examining how issues relating to dis/ability are a critical part of discourses around walking, and highlight inequities in access and the language we use to discuss it.We are particularly proud of Chingshun Sheu’s article, “Forced Excursion: Walking as Disability in Joshua Ferris’s The Unnamed”, which engages with disability theory in its discussion of Ferris’s 2010 novel. In Ferris’s text, the protagonist’s involuntary stints of walking to exhaustion appear as disability, affecting his work, relationships and ultimately, his mortality. Sheu uses the text to explore the complexity and limitations of disability models, noting that “disability exists only at the confluence of differently abled minds and bodies and unaccommodating social and physical environs.”Walking Is PosthumanChantelle Bayes approaches these unaccommodating environs from a different angle, discussing how “marginalised groups are usually the most impacted by the strict control and ordering of contemporary urban spaces in response to utopian imaginaries of who and what belong.” Bayes’s article, “The Cyborg Flâneur: Reimagining Urban Nature through the Act of Walking”, recasts Benjamin’s flâneur as cyborg, drawing on feminist writings from Debra Benita Shaw, Rob Shields, and Donna Haraway—the latter of whom is particularly influential for her recent contributions to eco-feminist thought. Bayes takes us into virtual urban spaces, by examining how a revisionist concept of flânerie can be reconfigured online, allowing “for new environmental imaginaries to be created.” Bayes’s concept is at once exciting and daunting: is walking through an app what we have to look forward to in the age of the Anthropocene? Will our cities continue to be more accommodating to the lucky few? Walking as a non-corporeal action is an unsettling thought, and intriguing for this discomfort. Walking Is GentrificationLet us guide you through these city streets to our next article, as Craig Lyons, Alexandra Crosby and H. Morgan Harris take us to Sydney’s inner West, an area becoming increasingly unaccommodating for many thanks to rising living costs. Their article, “Going on a Field Trip: Critical Geographical Walking Tours and Tactical Media as Urban Praxis in Sydney, Australia”, situates us in Marrickville, which they remind us is “unceded land of the Cadigal and Wangal people of the Eora nation who call the area Bulanaming.” Already this space is contested, as all Australian urban spaces all, palimpsests of Indigeneity, colonisation, and capital. Field Trip recognises this layering, operating as “a critical geographical walking tour through an industrial precinct,” prompting participants to take part in an act of resistance merely by walking the space.It recalls Mirror Sydney, writer Vanessa Berry’s blog (a book of the same name was published this year) that maps Sydney’s disappearing quirks. In a June entry, she notes after a walk that “in the last week new signs have gone up, signs for the impending auction of the two warehouses that make up the green building: ‘Invest, Occupy or Redevelop.’ It’s the last option that has Marrickvillians nervous” (Berry). These redevelopment nerves are confronted by Lyons, Crosby, and Harris as they examine gentrification in the area, as developers seek to exploit the area’s diverse population to attract wealth. They see their walking tour as a work of activism, a way of confronting the rapid gentrification of their city, stating that “via a community-led, participatory walking tour like Field Trip, threads of knowledge and new information are uncovered. These help create new spatial stories and readings of the landscape, broadening the scope of possibility for democratic participation in cities.”Walking Is PoliticalBeing able to walk is to exercise democracy. Last year in Australia, Clinton Pryor, a Wajuk, Balardung, Kija and a Yulparitja man, walked from Perth, near his home in Western Australia, to Canberra, to protest the treatment of First Nations peoples in Australia (Morelli). Indeed, one of the places where Pryor, dubbed “the Spirit Walker”, met his most rapturous welcome was in Sydney’s Redfern, not far from Marrickville. When Pryor reached Redfern, and the crowd that awaited him, he said, “I just walked in here and can’t tell you what Redfern has meant to us all over the years. Everyone knows Redfern is where we made our stand,” referring to the place’s reputation as the heartland of Australia’s Black Power movement (Murphy).Pryor’s walk demonstrates ambulatory political power—it became a march. Alina Haliliuc transports us to Bucharest, far from Australia’s dusty roads, in her article “Walking into Democratic Citizenship: Anti-Corruption Protests in Romania’s Capital”. Like Pryor, the subjects of her article “have been using their bodies in public spaces to challenge politicians’ disregard for the average citizen.” Haliliuc draws attention to the how the Romanian public have mobilised, marching the streets and affecting real change, striving—or striding—for democracy in a region plagued by increasing political instability. Walking Is ArtFor about three years, from 1972, American artist Adrian Piper would dress up as a man she dubbed the “Mythic Being”, donning an afro wig, a moustache and sunglasses, walking the streets of New York City presenting as a man. She documented some of these public appearances in works that appeared in her 2018 retrospective at New York’s Museum of Modern Art (MoMA) titled “Adrian Piper: A Synthesis of Intuitions 1965-2016”. John Bowles writes that Piper, who is mixed race, uses the Mythic Being figure to “engage critically with popular representations of race, gender, sexuality, and class, challenging viewers to accept personal responsibility for xenophobia, discrimination, and the conditions that allow them to persist” (257). After being lucky enough to view the MoMA exhibition earlier this year, I was reminded of the Mythic Being when reading Derrais Carter’s article, “Black Wax(ing): On Gil Scott-Heron and the Walking Interlude”. Carter examines Scott-Heron’s walks through Washington, DC as shown in the 1982 film about the musician, Black Wax. Like much of Piper’s oeuvre, the film is a meditation on race and power in the United States, splicing footage of live performances with “walking interludes” such as Scott-Heron strolling past the White House with his toddler daughter. Carter remarks that he is “interested in the film as a wandering text, one that pushes at tensions in order to untether the viewer from a constricting narrative about who they might be”. Walking can perform this untethering, at once generating and diffusing tension about identity and space. Scott-Heron’s cinematic strolls through DC, filmed when conservative President Ronald Reagan was at the height of his power, demonstrate how walking can be a subversive, revolutionary form of artistic expression. Walking Is WayfindingIn the feature article of this special issue, “Walking as Memorial Ritual: Pilgrimage to the Past”, Susan Sigre Morrison explores the complex relationship between the human and the nonhuman and centres on pilgrimage to shape this discussion. Morrison traces four pilgrimages she has taken as a young child through to her adulthood, reflecting on memory, ecocriticism, the sacred, and the Anthropocene along the way. Thickly woven, Morrison’s writing ranges between her own memories, the limestone of the Jurassic, the life of a small insect she encounters in a meal, and extracts from her mother’s diary entries telling of hikes she undertook with the child Morrison. Throughout, Morrison dwells on Donna Haraway’s concept of “making kin”, and asks, “How can narrative avoid the anthropocentric centre of writing, which is inevitable given the human generator of such a piece?”In thinking about walking and her body, walking and memory, walking and the nonhuman world, walking in the city and the country, Morrison lays down the suggestions of paths that many of the articles in this special issue then follow. “Landscape not only changes the writer, but writing transforms the landscape and our interaction with it”, Morrison writes, voicing a sentiment that, in various ways, many of the authors in this issue, and the scholars and writers they discuss, hold to be true, and fascinating, and from which so much work and thought around walking springs.Why do we walk? This is the question that we as editors kept returning to, when first we had the idea to collate a special issue on walking. While the history of walking is a well-trodden path, reaching back to the Romantics in England, the flâneurs in Paris, and the psychogeographers in cities everywhere, we resolved to look to the walkers of the contemporary world for this issue. In an age of increasingly sophisticated and prevalent technology, what is the role of the embodied act, the lived experience, of walking? With this special issue, it is our pleasure to offer a selection of work that speaks to why we walk, how we walk, and what walking means in contemporaneity. We thank the contributors, and those who expressed their interest in contributing, as well as the anonymous peer reviewers, for their work—and we hope that this issue might inspire, or prompt, or remind you, the reader, to search out your own walks.ReferencesBerry, Vanessa. “The Ming On Building”. Mirror Sydney, 15 June 2018. 4 Oct. 2018 <https://mirrorsydney.wordpress.com/2018/06/15/the-ming-on-building/>.Bowles, John Parish. Adrian Piper: Race, Gender, and Embodiment. Durham: Duke University Press, 2011.Elkin, Lauren. Flâneuse: Women Walk the City in Paris, New York, Tokyo, Venice and London. London: Vintage, 2016.Morelli, Laura. “Spirit Walker, Clinton Pryor Reaches Redfern on His Walk for Justice.” NITV, 11 Aug. 2017. 4 Oct. 2018 <https://www.sbs.com.au/nitv/nitv-news/article/2017/08/11/spirit-walker-clinton-pryor-reaches-redfern-his-walk-justice>.Murphy, Damien. “Long Walk for Justice: ‘Spiritual Walker’ Clinton Pryor Crosses the Country for His People.” Sydney Morning Herald, 10 Aug. 2017. 4 Oct. 2018 <https://www.smh.com.au/national/nsw/long-walk-for-justice-spiritual-walker-clinton-pryor-crosses-the-country-for-his-people-20170810-gxtsnt.html>.Solnit, Rebecca. Wanderlust: A History of Walking. London: Granta, 2014.