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

  • Groups seek electronic collision alert devices on big trucks
    February 20, 2015
    The US Advocates for Highway and Auto Safety, the Truck Safety Coalition, the Center for Auto Safety and Road Safe America have filed a petition with the National Highway Traffic Safety Administration (NHTSA) requesting that the agency initiate rulemaking to require forward collision avoidance and mitigation braking (F-CAM) systems on all new large trucks and buses with a gross vehicle weight rating (GVWR) of 10,000 pounds or more. F-CAM technology uses radar and sensors to first alert the driver and then t
  • Study forecasts growth of self-driving cars
    January 7, 2014
    In its latest study, “Emerging Technologies: Autonomous cars—not if, but when,”, IHS Automotive forecasts total worldwide sales of self-driving cars (SDC) will grow from nearly 230 thousand in 2025 to 11.8 million in 2035 – seven million SDCs with both driver control and autonomous control and 4.8 million that have only autonomous control. In all, there should be nearly 54 million self-driving cars in use globally by 2035. The study anticipates that nearly all of the vehicles in use are likely to be self
  • The downside of driverless vehicles
    October 27, 2016
    Driverless cars will have a detrimental effect on congestion and security while the road safety benefits can be achieved sooner and cheaper using ADAS, argues Colin Sowman. Many Governments are consulting about the introduction of driverless vehicles and even running trials. As 70% or 80% of crashes are caused by human error, the promise of a crash-free future of driverless, self-driving or autonomous vehicles (call them what you will) is alluring, as are the claims of reduced congestion and lower emissions
  • Cost of global road deaths & injuries: $3.6 trillion a year, says iRAP
    August 16, 2024
    Latest annual Safety Insights Explorer report reveals scale of human and financial burden