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

  • Polarisation is glaringly obvious, says Sony
    December 3, 2018
    Glare from the sun is a factor in a large number of road accidents – many of them fatal. But there is a solution at hand: using polarisation can mitigate the effect of glare and improve ITS camera enforcement, explains Stephane Clauss The effect of glare on driver safety has been well documented. A 2013 UK study by the country’s largest driver organisation, the AA, calculated sun glare was a contributing cause in almost 3,000 road accidents in 2012 alone. This represented one in 33 accidents on Britain’s
  • AI is creating road maintenance savings
    July 30, 2021
    Artificial intelligence is starting to create savings for hard-pressed local authorities when it comes to road maintenance. David Crawford reviews recent advances in cost and performance control
  • Copenhagen to showcase ITS in action at ITSWC 2018
    December 18, 2017
    As delegates head for the 2017 ITS World Congress in Montreal, we talk to Copenhagen mayor Morten Kabell about why his city is the ideal location for next year’s event. It may have been a long time coming but the ITS World Congress will be in Copenhagen in 2018 and there can be few more fitting places to host the event. By any number of metrics - interconnected transport, cycle commuting, safer streets, reduced pollution, sustainable energy and quality of life - the Danish capital has implemented what m
  • Germany's approach to adaptive traffic control
    February 3, 2012
    Jürgen Mück, Siemens AG, describes the three-level approach taken in Germany to adaptive network control