The high mode share of bikers in Boulder, Colorado allowed researchers to verify findings already documented by researchers in Europe.
"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,'" according to an article on PhysOrg.
"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."
FULL STORY: Study shows more bicyclists on road means fewer collisions

Rethinking Redlining
For decades we have blamed 100-year-old maps for the patterns of spatial racial inequity that persist in American cities today. An esteemed researcher says: we’ve got it all wrong.

Planetizen Federal Action Tracker
A weekly monitor of how Trump’s orders and actions are impacting planners and planning in America.

Walmart Announces Nationwide EV Charging Network
The company plans to install electric car chargers at most of its stores by 2030.

New State Study Suggests Homelessness Far Undercounted in New Mexico
An analysis of hospital visit records provided a more accurate count than the annual point-in-time count used by most agencies.

Michigan Bills Would Stiffen Penalties for Deadly Crashes
Proposed state legislation would close a ‘legal gap’ that lets drivers who kill get away with few repercussions.

Report: Bus Ridership Back to 86 Percent of Pre-Covid Levels
Transit ridership around the country was up by 85 percent in all modes in 2024.
Urban Design for Planners 1: Software Tools
This six-course series explores essential urban design concepts using open source software and equips planners with the tools they need to participate fully in the urban design process.
Planning for Universal Design
Learn the tools for implementing Universal Design in planning regulations.
City of Moorpark
City of Tustin
City of Camden Redevelopment Agency
City of Astoria
Transportation Research & Education Center (TREC) at Portland State University
Regional Transportation Commission of Southern Nevada
Toledo-Lucas County Plan Commissions