Featured Research

from universities, journals, and other organizations

More bicyclists on road means fewer collisions, study shows

Date:
June 24, 2014
Source:
University of Colorado Denver
Summary:
Bicyclist safety significantly increases when there are more bikes on the road, according to a study examining collisions between bicycles and motorists. This finding could be attributed to a 'safety in numbers effect.' As bicycling 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 bicycling are not just safer for cyclists but for all road users," one author said. "Improving the streets to better accommodate bicycles may enhance safety for everyone."

A University of Colorado Denver study examining collisions between bicycles and motorists, shows bicyclist safety significantly increases when there are more bikes on the road, a finding that could be attributed to a "safety in numbers effect."

Related Articles


The study focused on Boulder, Colorado, which has one of the highest rates of bicycling in the country at about 12 percent of the population.

That makes it one of the few U.S. cities with enough bicycling to achieve the safety benefits already documented by researchers in Europe, said study co-author Wesley Marshall, PhD, PE, assistant professor of civil engineering at CU Denver's College of Engineering and Applied Science.

And Boulder's close proximity to CU Denver's downtown campus offered an ideal opportunity for the researchers and students.

"I was glad to be able to do this practical, hands-on research on bicyclist safety while a student at CU Denver," said study co-author Krista Nordback, PhD, PE.

The researchers wanted to create safety performance functions (SPFs) for bicycles in Boulder. SPFs 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 bikes.

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 bicycle count data.

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

The researchers found that the chance of collision decreased with more bicyclists.

The risk of accident was relatively high at intersections with less than 200 bicyclists per day.

"Anywhere above this threshold is where we are seeing the largest safety benefits," Marshall said.

The reasons for this remain unknown.

"Other studies have hypothesized that when drivers expect to see a significant number of bicyclists on the street, their behavior changes," Marshall said. "They are more likely to look over their shoulder for a bicyclist before taking a right turn."

Cyclists may also be attracted to safer areas.

"But we think there is even more to the story and we'll be looking for that in our next study," said Marshall.

The results could have national implications.

As bicycling 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 bicycling 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."


Story Source:

The above story is based on materials provided by University of Colorado Denver. Note: Materials may be edited for content and length.


Journal Reference:

  1. Krista Nordback, Wesley E. Marshall, Bruce N. Janson. Bicyclist safety performance functions for a U.S. city. Accident Analysis & Prevention, 2014; 65: 114 DOI: 10.1016/j.aap.2013.12.016

Cite This Page:

University of Colorado Denver. "More bicyclists on road means fewer collisions, study shows." ScienceDaily. ScienceDaily, 24 June 2014. <www.sciencedaily.com/releases/2014/06/140624093328.htm>.
University of Colorado Denver. (2014, June 24). More bicyclists on road means fewer collisions, study shows. ScienceDaily. Retrieved January 31, 2015 from www.sciencedaily.com/releases/2014/06/140624093328.htm
University of Colorado Denver. "More bicyclists on road means fewer collisions, study shows." ScienceDaily. www.sciencedaily.com/releases/2014/06/140624093328.htm (accessed January 31, 2015).

Share This


More From ScienceDaily



More Science & Society News

Saturday, January 31, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

China's "Great Firewall" Frustrates Internet Users

China's "Great Firewall" Frustrates Internet Users

Reuters - News Video Online (Jan. 31, 2015) The Chinese government moves to tighten regulations for virtual private network (VPN) services that are used to access websites and services normally blocked in China. That&apos;s affected many internet users in the country. Yiming Woo reports. Video provided by Reuters
Powered by NewsLook.com
Excuses, Excuses: Weirdest Reasons People Give For Tardiness

Excuses, Excuses: Weirdest Reasons People Give For Tardiness

Newsy (Jan. 30, 2015) CareerBuilder surveyed around 5,000 workers and human resources managers nationwide to compile a list of strange excuses employees used when tardy. Video provided by Newsy
Powered by NewsLook.com
CDC: Get Vaccinated for Measles

CDC: Get Vaccinated for Measles

Reuters - US Online Video (Jan. 30, 2015) The CDC is urging people to get vaccinated for measles amid an outbreak that began at Disneyland and has now infected more than 90 people. Linda So reports. Video provided by Reuters
Powered by NewsLook.com
Obama To Outline New Plan For Personalized Medicine

Obama To Outline New Plan For Personalized Medicine

Newsy (Jan. 30, 2015) President Obama is expected to speak with drugmakers Friday about his Precision Medicine Initiative first introduced last week. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Science & Society

Business & Industry

Education & Learning

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins