AUTONEWS

Study finds 40 km/h zones cut pedestrian crashes by 24%
New research from the Monash University Accident Research Centre (MUARC) has found that lowering speed limits to 40 km/h on certain Victorian roads can significantly improve road safety, particularly for pedestrians. The findings provide evidence to guide potential further expansion of 40 km/h zones across the state.
The study, conducted as part of MUARC's Baseline Road Safety Research Program, analyzed crash data and driver behavior in areas where 40 km/h speed limits had been introduced, including local roads, shopping strips, and high pedestrian zones. It also surveyed drivers to better understand attitudes and compliance with lower speed limits. The research is published in the journal Monash University.
The study found that roads with newly implemented 40 km/h speed limits had a 9.7% reduction in casualty crashes, and a 23.8% reduction in crashes involving pedestrians. The research highlights how strategic implementation of lower speed limits in urban areas can reduce injury risk and align with Safe System principles, particularly in areas with high foot traffic or vulnerable road users.
Professor Stuart Newstead, MUARC Director, said the findings show a clear safety benefit and provide evidence for policymakers in considering any future program expansion.
"Our study shows that implementing 40 km/h zones has proven benefit in reducing crash and injury rates, especially in areas where pedestrians are most at-risk," Professor Newstead said.
"Expanding these lower speed zones in local streets and busy pedestrian areas could contribute significantly to reducing road trauma. But to be effective, this must be coupled with improved signage, education and data collection."
The study considered the potential benefits of expanding 40 km/h zones, especially on local roads outside metropolitan Melbourne, where estimated crash reductions could be as high as 131 crashes annually. It also identified the value of better road asset data and implementation tracking to refine future evaluations.
MUARC researchers also noted that, while self-reported speeding behavior suggests general support and compliance with 40 km/h limits, actual driving patterns reveal a discrepancy that must be addressed through targeted interventions and public engagement.
Further research is recommended to enhance data accuracy, improve understanding of unintentional speeding in low-speed zones, and explore how infrastructure design and enforcement can better support compliance.
Why are 40 and 30 km/h zones so much safer?
Lower speeds:
1. Reduce the risk of a crash
2. Reduce the risk of death or injury when a crash does occur
The key difference between a crash at different speeds is the energy or force someone is
exposed to. A crash occurring at 60 km/h results in four times the energy transfer compared to
a crash at 30 km/h, even though the speed is only two times as much.
In complex urban environments with multiple road users, drivers “are more likely to reach the
threshold of their information processing capabilities when traveling at higher speeds.” At safer
speeds, “decisions can be made in a more timely manner.”
In addition, drivers are more willing to give way to pedestrians on crossings at lower speeds.
Stopping distance...Stopping distance is made up of:
● Reaction distance – the distance travelled in approximately 1.5 seconds during which no
braking is happening as the driver processes the need to stop
● Braking distance – the distance from when the driver starts braking to when the vehicle
stops.
Similar to energy, braking distance is four times longer when speed is only two times higher.
Travelling at a speed of 50 km/h, a vehicle will require about twice the braking distance compared to travelling at 30 km/h. This assumes drivers recognise the critical situation and respond quickly.
Studies of safer speed zones 40 km/h limits...In 2019, the speed limit in the Cairns CBD was reduced from 50 to 40 km/h. Comparing the two years before and after, road injuries reduced by 24% and there was a 36% reduction in walker and bike rider injuries.
In 2012 and 2016 the City of Stonnington reduced the speed limit from 50km/h to 40km/h in parts of Toorak and Prahran in Melbourne. The total number of crashes reported by police
reduced from 70 to 38 (when comparing the three-year periods before and after they were introduced) and the number of people injured fell 42%, from 137 to 79. The number of vulnerable road users (people walking, riding a bike or motorbike) who were injured fell from 46 to 22, although the number of serious injuries remained stable.
30 km/h limits...A Canadian study found that reducing the speed limit from 40km/h to 30km/h on more than 300km of local roads in one area resulted in a 28% decrease in crashes with walkers and a 67% decrease in serious and fatal injuries.
An analysis of 20 years of data from London found that introducing 32 km/h (20 mph) speed limits resulted in an estimated 42% drop in injury crashes with the effect on the numbers killed or seriously injured slightly greater than for injuries overall. The numbers of killed or seriously injured children were reduced by half. There was an estimated 32% decrease in pedestrian injuries.
A review of the impact of 30km/h speed limits in 40 cities across Europe found that the average reduction in crashes was 23%, the average reduction in injuries was 38% and for fatalities 37%.
Encouraging walking and bike riding...International organisations including the UN have recognised the role that 30 km/h traffic speeds play in creating safer, more welcoming conditions for walking and cycling in the context of broader urban planning.
Evidence shows that 30 km/h streets where people mix with traffic not only save lives, but also promote walking, cycling and a move towards zero-carbon mobility.
In town centres, lower traffic speeds are a typical outcome of streetscape improvements (sometimes including speed limit reduction) that are also usually associated with higher pedestrian volumes and, where measured, economic activity. But research that is able to draw direct connections between speed and pedestrian activity is relatively rare.
A study from Basel, Switzerland, found a speed limit of 20 km/h on local roads resulted in residents being two to three times more likely to talk, play, observe and sit in the public space compared to streets with a speed limit of 50 km/h.
A study in San Fransisco found that increased traffic speed of 10 mph was associated with reduction in the distance people were willing to walk of an average 60m.
A 32 km/h (20 mph) speed limit pilot scheme in South Central Edinburgh, UK, found that after speed limits were reduced from 30 mph, residents were strongly supportive and reported improved safety for children walking and playing, and improved walking and cycling conditions. There was a 7% increase in the number of trips walked, a 5% increase in the number of bicycle trips and a 3% reduction in car journeys in the year after the scheme was introduced.
Provided by Monash University









