Urban heat islands and transport infrastructure: Why Australia’s tram systems lack green corridors despite proven cooling and biodiversity benefits

Indigenous land stewardship in Australia, such as the use of native grasses and fire management by the Noongar and Arrernte peoples, demonstrates centuries-old practices of creating ‘cool corridors’ that regulate microclimates and support biodiversity. These traditions are rooted in a reciprocal relationship with land, where infrastructure is designed to regenerate rather than degrade ecosystems. However, modern urban planning in Australia largely ignores these knowledge systems, favouring monoculture lawns and exotic species that require high water and maintenance. Integrating indigenous fire ecology and native plantings into tram corridors could reduce heat islands while restoring cultural landscapes.

Melbourne’s tram network, established in the 1880s, originally featured native grasses and shrubs along tracks, reflecting a pre-car urban design ethos that valued ecological integration. The shift to asphalt and concrete in the mid-20th century, driven by car-centric planning and suburban sprawl, erased these green corridors, contributing to the city’s current urban heat island effect. European cities like Amsterdam and Zurich retained green tram tracks through deliberate policy choices, proving that historical precedents exist for integrating transit and ecology. Australia’s failure to adopt such models reflects a broader amnesia about its own transit history and a preference for imported car-centric urbanism.

Japanese tram systems, such as those in Hiroshima, incorporate native plant species and seasonal aesthetics to mitigate heat while celebrating cultural heritage, showing how transit infrastructure can embody ecological and spiritual values. In Bogotá, Colombia, the ‘green routes’ along bus rapid transit corridors blend indigenous agroecological principles with modern transit, addressing heat and social equity simultaneously. These examples highlight how transit systems can be designed to serve multiple ecological and cultural functions, rather than being reduced to mere mobility infrastructure. Australia’s lack of such integrative approaches reflects a narrow, technocratic vision of urban design.

Studies show that green tram tracks can reduce surface temperatures by 5–10°C compared to asphalt, while also lowering particulate pollution and supporting pollinator biodiversity. Research from the University of Melbourne demonstrates that native grasses and succulents in tram corridors improve stormwater absorption and reduce the urban heat island effect by up to 30% in adjacent areas. However, Australia lacks national standards for green tram infrastructure, and existing trials (e.g., in Adelaide) are underfunded and poorly monitored. The scientific consensus supports green tram tracks, but implementation is hindered by fragmented governance and short-term cost-benefit analyses.

Green tram tracks can be designed as living artworks, integrating indigenous plant species and seasonal blooms to create sensory-rich urban corridors that nourish the spirit as well as the body. In many cultures, transit systems are not just functional but sacred, such as the Japanese concept of ‘satoyama’ landscapes that blend human use with ecological harmony. Australia’s urban spaces often lack such spiritual and artistic dimensions, reducing transit corridors to utilitarian pathways devoid of beauty or meaning. Reimagining tram tracks as cultural corridors could restore a sense of place and connection to land in Australian cities.

Modelling by the CSIRO suggests that scaling green tram tracks across Australia’s major cities could reduce urban heat-related deaths by 20% by 2050 while cutting transport emissions by 5%. Scenario planning in Melbourne indicates that integrating native plantings into tram corridors could create 500+ hectares of new green space, supporting biodiversity corridors and improving mental health outcomes. However, without coordinated federal investment and policy mandates, these benefits remain theoretical. Future-proofing Australian cities requires treating tram corridors as critical green infrastructure, not optional amenities.

Marginalised communities, particularly Indigenous Australians and low-income renters, bear the brunt of urban heat due to lack of green spaces and proximity to high-traffic areas. Elderly residents, children, and people with disabilities are disproportionately affected by heat stress, yet their voices are rarely included in transport planning decisions. The absence of community-led design processes in tram corridor projects means that solutions often reflect the priorities of planners and engineers rather than those most impacted. Centering marginalised voices could shift the focus from ‘beautification’ to equity and resilience.