Blacktown City Council is planting trees along streets where a focus on motorists once left them barren, following award-winning research that could lead to a cooler, healthier and safer community.
A council-led team of multi-disciplinary researchers challenged the motorist-centric attitude against street trees and found a range of risks to pedestrians, cyclists, home and business owners, and broader community from not planting.
The study was called 'The Risk of Not Planting Trees Along our Streets'.
This risk-based assessment found planting trees along streets with speed limits of up to 70km/h could improve cyclist and pedestrian safety, community mental and physical health, temperature and infrastructure condition while keeping the community safe.
The team included UNSW Sydney and University of Sydney health researchers, and Western Sydney University environmental scientists. Experts from Austroads, Local Government NSW, Transport for New South Wales, Western Sydney Local Area Health District, Western Sydney Regional Organisation of Councils and legal practitioners also contributed.
Council has won five major awards for the study and Blacktown City Mayor Brad Bunting was proud of the results.
"Council is leading the way in urban design and the findings of this study will benefit current and future generations of our community," he said.
"The risk is not the planting of trees, it's what happens when we don't.
"Blacktown City is vulnerable to extreme heat so we want to plant trees where it's practical to keep our community cool, active and above all safe."
Artificial intelligence was used to produce models of roads before and after street trees, providing site-specific risk assessments of safety and cooling.
A decade of fatal crash data in Blacktown City was analysed as part of the study. This found speeding and alcohol were the main causes of cars leaving the road in these crashes.
Planting trees would increase crash risk by just two in 100 million, according to the analysis. This was greatly outweighed by the benefits to the wider community.
Council has since changed its policy and plants trees along streets with speed limits of up to 70km/h, subject to safety assessments.
This has included locations such as Luxford Rd at Emerton, Vardys Rd at Kings Langley, Lucretia Rd at Seven Hills and Palmyra Avenue at Willmot.
Professor Sebastian Pfautsch, who specialises in urban management and planning at Western Sydney University, was among the experts who contributed to the findings.
"Our study clearly showed that the collective benefits of more shade from tall street trees – cooler streets, better air quality, less noise, more walking opportunities and greater biodiversity – far outweigh the risks such trees may pose to traffic," he said.
"It's a great example of a trans-disciplinary and evidence-based approach to deliver better policy outcomes for the communities of Blacktown."
Professor Xiaoqi Feng, an expert in Urban Health and Environment at UNSW and Honorary Professorial Fellow at The George Institute for Global Health, was part of the team.
"It's been an honour to translate over a decade of research I've led with Professor Thomas Astell-Burt, highlighting the powerful mental, physical, and social health benefits of urban greening," she said.
"I am looking forward to seeing a greener, more active and socially connected community in Blacktown City."
Professor Thomas Astell-Burt, from Cities and Planetary Health at the University of Sydney and an Australian Research Council Future Fellow, was another who contributed.
"The research that Professor Feng and I have led shows clearly that achieving a 30% canopy cover meaningfully reduces risks of heart attacks, diabetes, hypertension, loneliness, mental ill-health - even dementia," he said.
"It is truly rewarding to be part of multisector research collaborations that drive tangible, real-world outcomes for health, sustainability, and climate action."
Professor Astell-Burt is also Principal Investigator, Westmead Applied Research Centre, Westmead Hospital.
The NSW Government funded the Council study.
'The risk of not planting trees along our streets' accolades
Winner - National Awards for Local Government, Road Safety (2025)
Winner - Parks & Leisure Australia NSW/ACT Research Award (2025)
Winner - Local Government NSW Excellence in Environment Awards (2024)
Winner - National Growth Areas Alliance Excellence and Innovation Awards (2024)
Winner - CivicRisk Mutual Excellence in Risk Management Awards (2024)
