More Bikes Lanes On Less Congested Roads

Comparison of before and after counts of vehicular volume-to-capacity ratio shows replacing car lanes with bike lanes may not adversely impact vehicle traffic when bike lanes are constructed on less congested streets.

1 minute read

April 15, 2014, 7:00 AM PDT

By Helen Brown


Gretchen Johnson and Aaron Johnson seek to answer how new bike lanes impact drivers, especially when they take the place of an existing vehicle lane: “It seems that unless a ton of people start commuting by bicycle, giving away a lane would cause increased car traffic. But is this really the case?”

By comparing vehicular volume-to-capacity (V/C) ratio before and after bike lanes have been added, Johnson and Johnson reveal that: “Taking away a lane does significantly increase the estimated V/C ratio during rush hour...But it’s not at a high enough V/C ratio where traffic will get really congested and start slowing down.”

Their recommendations regarding where to place new bike lanes: “Bike lanes don’t cause a lot more congestion if you put them on the right streets…if you start with roads that are well under capacity, you’ll only increase the congestion a little bit. And it may not even be noticeable.” 

Friday, April 11, 2014 in Five Thirty Eight - Life

portrait of professional woman

I love the variety of courses, many practical, and all richly illustrated. They have inspired many ideas that I've applied in practice, and in my own teaching. Mary G., Urban Planner

I love the variety of courses, many practical, and all richly illustrated. They have inspired many ideas that I've applied in practice, and in my own teaching.

Mary G., Urban Planner

Cover CM Credits, Earn Certificates, Push Your Career Forward

Logo for Planetizen Federal Action Tracker with black and white image of U.S. Capitol with water ripple overlay.

Planetizen Federal Action Tracker

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

5 hours ago - Diana Ionescu

Aerial view of town of Wailuku in Maui, Hawaii with mountains in background against cloudy sunset sky.

Maui's Vacation Rental Debate Turns Ugly

Verbal attacks, misinformation campaigns and fistfights plague a high-stakes debate to convert thousands of vacation rentals into long-term housing.

July 1, 2025 - Honolulu Civil Beat

Person wearing mask walking through temporary outdoor dining setup lined with bistro lights at dusk in New York City.

Restaurant Patios Were a Pandemic Win — Why Were They so Hard to Keep?

Social distancing requirements and changes in travel patterns prompted cities to pilot new uses for street and sidewalk space. Then it got complicated.

June 19, 2025 - Diana Ionescu

Aerial view of new neifhborhood under construction with enpty lots in foreground.

In California Battle of Housing vs. Environment, Housing Just Won

A new state law significantly limits the power of CEQA, an environmental review law that served as a powerful tool for blocking new development.

6 hours ago - CALmatters

Low-rise Pearl Sreet mall in Boulfer, Colorado.

Boulder Eliminates Parking Minimums Citywide

Officials estimate the cost of building a single underground parking space at up to $100,000.

7 hours ago - Boulder Reporting Lab

Two-story buildings with porches in walkable Florida neighborhood.

Orange County, Florida Adopts Largest US “Sprawl Repair” Code

The ‘Orange Code’ seeks to rectify decades of sprawl-inducing, car-oriented development.

July 2 - CNU Public Square