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

  • San Diego: Let there be (street)light
    March 30, 2020
    The influence of intelligent streetlights is spreading. David Crawford finds that San Diego’s deployment – and attendant legislation – may offer a blueprint for other cities going forward
  • Study finds red-light cameras reduce crashes
    July 3, 2013
    A study carried out by Baton Rouge, Louisiana’s Department of Public Works shows drops in both traffic crashes and violations at selected intersections in the five years since the city launched a traffic light camera program. The study evaluated intersections where traffic cameras were installed in 2008 and 2009 by comparing the average number of crashes in the years before and after the cameras took effect, and showed a sharp decline in right-angle crashes - considered the most dangerous type of collisions
  • ITS Australia announces Max Lay award winner
    October 8, 2020
    Dr Peter Sweatman receives lifetime achievement recognition for his transport career
  • Video analytics enhances urban rail safety
    December 16, 2016
    David Crawford explores some promising innovations for North American commuters. North America is experiencing a surge in commuter rail and metro development. The US now has 75 light rail and metro networks in operation; and California, in particular, is actively exploring ways of developing the state’s existing passenger rail operations into a fully integrated system.