Do Bikes Slow Down Car Traffic? Actually, No

Do Bikes Slow Down Car Traffic? Actually, No


It happens to every driver at some point. You’re in a rush downtown, late to a meeting, and trying to make up time, when suddenly you find yourself stuck behind a bicyclist. It feels a bit like a double whammy — because as everyone knows, bikes travel far slower than motor vehicles and hold up traffic in general.

Only, it turns out, that particular assumption just hit a speed bump.



So says a study published in June 2020, in Transportation Research Record: Journal of the Transportation Research Board. Three researchers from Portland State University found that on low-speed, low-volume roads city roads – ones without bicycle lanes – motor vehicle speeds varied by 1 mph (1.6 kph) or less when bicyclists were present.

Doubters, commence your scoffing.

It’s easy for drivers to assume that bikes cause slowdowns, which then cascade into potentially treacherous, backed-up traffic. But consider pumping the brakes on your skepticism.

The researchers completed their study in Portland, Oregon, by some estimates home to some of the worst traffic in the United States. They chose a very specific question to answer: “Do bicycles reduce passenger car travel speeds on urban roads without bicycle lanes?”

As part of their investigation, they observed six different roadways at various times, including rush hour. They looked for vehicles following other motor vehicles, and then those that followed cyclists.

After a detailed comparative analysis, they found that there was only a 1 mph speed differential when cyclists were on the roadway, hardly enough to cause a backup, much less the gridlock that makes motorists moan in agony.

Naturally, on downhill slopes, there was even less chance that car drivers would have cause for concern, as cyclists harnessed gravity to increase their speed. And of course, e-bikes, which have a power-assist feature that boosts their speed, were even less likely to be overtaken by cars, no matter the incline.

“The hope is that our study dissuades policymakers from tossing out shared roadways as a viable option because of the perception that bicyclists will impede the mobility and speed of drivers,” said Jaclyn Schaefer, one the study authors, in a press statement. “While the preference is to separate modes through separated, protected bike lanes, that’s not always possible in every urban setting.”

The researchers plan to expand their study to include a greater variety of roadways, traffic volumes and other variables to see how cyclists affect other types of vehicular dynamics.

Print |
Citation & Date |

Science · Previous Story

Next Story · Science


Drivers Who Merge at the Last Minute May Be Annoying, But They’re Right

How Traffic Works

Do Bike Helmets Save Lives? Or Do They Hurt Cycling?




Get the best of HowStuffWorks by email!

Keep up to date on: Latest Buzz · Stuff Shows & Podcasts · Tours · Weird & Wacky

Copyright © 2020 HowStuffWorks, a division of InfoSpace Holdings, LLC, a System1 Company

Privacy Choices

We use cookies to personalise content and ads, to provide social media features and to analyse our traffic. We also share information about your use of our site with our social media, advertising and analytics partners who may combine it with other information that you’ve provided to them or that they’ve collected from your use of their services. You consent to our cookies if you continue to use our website.


Do Bikes Slow Down Car Traffic? Actually, No

Research & References of Do Bikes Slow Down Car Traffic? Actually, No|A&C Accounting And Tax Services

Author: promotiondept

Leave a Reply