Effect of reducing the posted speed limit to 30 km per hour on pedestrian motor vehicle collisions in Toronto, Canada - a quasi experimental, pre-post study

Abstract

Background: Pedestrian related deaths have recently been on the rise in Canada. The effect of changing posted speeds on the frequency and severity of pedestrian motor vehicle collisions (PMVC) is not well studied using controlled quasi-experimental designs. The objective of this study was to examine the effect of lowering speed limits from 40 km/h to 30 km/h on PMVC on local roads in Toronto, Canada. Methods: A 30 km/h speed limit on local roads in Toronto was implemented between January 2015 and December 2016. Streets that remained at a 40 km/h speed limit throughout the study period were selected as comparators. A quasi-experimental, pre-post study with a comparator group was used to evaluate the effect of the intervention on PMVC rates before and after the speed limit change using repeated measures Poisson regression. PMVC data were obtained from police reports for a minimum of two years pre-and post-intervention (2013 to 2018). Results: Speed limit reductions from 40 km/h to 30 km/h were associated with a 28% decrease in the PMVC incidence rate in the City of Toronto (IRR = 0.72, 95% CI: 0.58-0.89). A non-significant 7% decrease in PMVC incidence rates were observed on comparator streets that remained at 40 km/h speed limits (IRR = 0.93, 95% CI: 0.70-1.25). Speed limit reduction also influenced injury severity, with a significant 67% decrease in major and fatal injuries in the post intervention period on streets with speed limit reductions (IRR = 0.33, 95% CI: 0.13-0.85) compared with a 31% not statistically significant decrease in major and fatal injuries on comparator streets (IRR = 0.69, 95% CI: 0.37-1.31). The interaction term for group and pre-post comparisons was not statistically significant (p = 0.14) indicating that there was no evidence to suggest a pre-post difference in IRRs between the intervention and comparator streets. Conclusions: Declines in the rate of PMVC were observed on roads with posted speed limit reductions from 40 km/h to 30 km/h, although this effect was not statistically greater than reductions on comparator streets.

Pedestrian Motor Vehicle Accidents and Fatalities in Botswana-An Epidemiological Study

“…Despite having stricter road traffic laws, there has been negligible improvement in road safety (Mphela, 2011). While the reduction of posted speeds has led to improvements on pedestrian safety in other countries as reported by Fridman et al (2020) and Marshall (2012), driver non-compliance remains a threat in Botswana. Improving law enforcement and nurturing driver compliance is ideal.…”

“…In areas where the road safety awareness messages were combined with engineering interventions (redesigning of pedestrian access roads), pedestrian collisions declined by as much as 79%. In Toronto, Canada a quasi-experimental study by Fridman et al (2020), where a posted speed limit was reduced from 40 to 30km/h, led to a 28% decrease in pedestrian road accidents compared to roads that were left at 40 km/h. However, Matsui and Oikawa (2019) found that pedestrian collisions that happen at low speeds tend to be more fatal than those happening at high speeds at signalized intersections during daytime.…”

Pilot study to evaluate school safety zone built environment interventions

“…36 Lowering the speed limits from 40 to 30 km/hour has been associated with a 29% decrease in child pedestrian motor vehicle collisions in Toronto. 27 ASE has been found to substantially reduce speeding, speed violations, collisions, injuries and deaths around schools. 37 38 Physical infrastructure changes related to traffic calming are important around schools, as this study found more than half of schools did not have any traffic calming measures at their frontages.…”

Why is necessary to reduce the speed in urban areas to 30 KM/H?

“…If we focus on the effects of speed reduction on pedestrian fatality risk we see that they are treated in many studies (De Pauw et al, 2014;De Pelsmacker and Janssens, 2007;Elvik, 2009;Fridman, 2020;Heydari et al al., 2014;Hussain et al, 2019;Rosén, 2009). A reduction in speed limits can help reduce the kinetic energy of the vehicle and therefore, the damage to the pedestrian.…”