Skip to main content

Study ‘shows more bicyclists on road means fewer collisions’

A study of cycle versus vehicle accidents carried out by the University of Colorado, Denver (CU Denver) has found that the chance of collision decreased with more cyclists. The risk of accident was relatively high at intersections with less than 200 cyclists per day. “Anywhere above this threshold is where we are seeing the largest safety benefits,” said co-author Wesley Marshall, PhD, PE, assistant professor of civil engineering at CU Denver’s College of Engineering and Applied Science. The reasons for
June 25, 2014 Read time: 2 mins
A study of cycle versus vehicle accidents carried out by the University of Colorado, Denver (CU Denver) has found that the chance of collision decreased with more cyclists. The risk of accident was relatively high at intersections with less than 200 cyclists per day.

“Anywhere above this threshold is where we are seeing the largest safety benefits,” said co-author Wesley Marshall, PhD, PE, assistant professor of civil engineering at CU Denver’s College of Engineering and Applied Science. The reasons for this remain unknown.

The study focused on Boulder, Colorado which has one of the highest rates of cycling in the country at about twelve percent of the population. This makes it one of the few US cities with enough bicycling to achieve the safety benefits already documented by researchers in Europe, according to Marshall.

The researchers wanted to create safety performance functions (SPFs) for bicycles in Boulder. These model the mathematical relationship between the frequency of crashes and major factors related to them. Yet while there are SPFs for vehicles, there are none for cycles. The authors created their SPF for Boulder by studying crashes at intersections throughout the city where more than two-thirds of collisions occur.  They compared the crash data to cycle count data.

“Fortunately, Boulder was one of the first cities to establish a bicycle counting program back in the late 90s,” Marshall said.

As cycling increases in cities across the U.S. each year, the results could have national implications. “In fact, we are beginning to find that cities with a high level of cycling are not just safer for cyclists but for all road users,” he said.  “Improving the streets to better accommodate bicycles may enhance safety for everyone.”

Related Content

  • Transport is evolving – and road safety must keep pace, says Parifex
    May 25, 2023
    France-headquartered Parifex works at the cutting edge of Lidar-based speed control systems. CEO Paul-Henri Renard discusses safety advances made in recent decades - and the causes of accidents that remain…
  • Does ADAS create as many problems as it solves
    September 23, 2014
    Victoria Banks and Neville Stanton [1] of Southampton University’s Transportation Research Group examine the real impact of creeping driver automation. Safety research suggests that 90% of accidents are thought to be a result of driver inattentiveness to unpredictable or incomplete information and the vision is that highly automated vehicles will lead to accident-free driving in the future.
  • We need to talk about AVs
    October 15, 2021
    Will driverless vehicles lead to more deaths and destroy more lives than their manual counterparts? Transport writer Colin Sowman argues that they will
  • Study finds rumble strips save lives on rural highways
    June 2, 2015
    A recently completed study shows that rumble strips are proving to be an effective and low-cost way to reduce crashes on Michigan's state highways. The Michigan Department of Transportation (MDOT) started a major rumble strip program for two-lane high-speed rural highways in 2008. Centre-line and shoulder rumble strips were installed on all MDOT rural, non-freeway highways with posted speed limits of 55 mph and appropriate paved lane and shoulder widths. To date, 5,700 miles of centre-line rumble strips