Skip to Content
Streetsblog New York City home
Streetsblog New York City home
Log In
Streetsblog

Portland Shows How to Get More Bang for Your Traffic Safety Buck

Three road diets in Portland have prevented a total of 252 collisions. Image: Bike Portland
Three road diets in Portland have prevented a total of 525 collisions. Graphic: Bike Portland
false

State DOTs like to justify hugely expensive highway-widening projects, like Milwaukee's $1.7 billion Zoo Interchange, partly on the grounds of safety. But if we really want to get a big bang for our transportation safety buck, fixing city streets makes a lot more sense.

Michael Andersen at Bike Portland reports that three local road diets completed between 1997 and 2003 cost a combined total of just $500,000 and have prevented more than 500 collisions:

A new city study shows the big payoff the city has quietly seen from a few uses of one of the least-understood tricks in traffic engineering: the 4-3 road diet.

Converting four general travel lanes to two plus a turn lane and (in some cases) painted bike lanes have prevented about 525 crashes on three Portland streets -- Northeast Glisan from 22nd to 32nd; Southeast 7th from Division to Washington; and Southeast Tacoma from 6th to 11th -- during the 16 years studied, the analysis released this week found. The number of traffic crashes on those streets dropped 37 percent.

Traffic volumes on those three streets, meanwhile, fell by an average 7.7 percent, suggesting that the safety and access improvements weren’t accompanied by major new burdens on drivers’ mobility.

The number of crashes being prevented on each of those streets, of course, continues to rise: by about 37 more every year among the three of them.

Now imagine if that money from the one highway widening project in Milwaukee was used instead to do 10,200 road diets.

Elsewhere on the Network today: Seattle Bike Blog announces the opening of the city's new Pronto bike-share system. Strong Towns shares readers' stories of trying to walk to the nearest grocery store. And Forward Lookout shares some data detailing the declining rate of return on highway spending.

Stay in touch

Sign up for our free newsletter

More from Streetsblog New York City

Wednesday’s Headlines: Return of Summer Streets Edition

Summer Streets is back and bigger than ever. Plus more news.

July 2, 2025

How Will Mamdani Govern? His Earlier MTA Advocacy Gives Some Hints

Mamdani spent his initial years as a state assemblyman cultivating relationships in and around the MTA while crafting his vision for "fast and free buses."

July 2, 2025

Brooklyn Judge Once Again Declines to Rip Up Bedford Ave. Protected Bike Lane… For Now

Well-connected lawyer Frank Seddio argued against the Bedford Avenue protected bike lane in court on Tuesday.

Money for Something: Funding OK’d, But Details Missing For ‘Dept. Of Sustainable Delivery’

The mayor got the Council to sign off on $6.1 million for the long-awaited “Department of Sustainable Delivery." But what's it mean? No one is talking.

July 1, 2025

Incoming Albany Mayor Could Help Safe Streets Movement Statewide

The state capital is built for the car and that is how it is experienced by our lawmakers. But could that change under a new mayor? Here's hoping.

July 1, 2025

Tuesday’s Headlines: Another Child Sacrificed to the SUV Edition

Stop de kindermoord! An 8-year-old boy killed by an SUV driver is the latest victim of America's obsession with big cars. Plus other news.

July 1, 2025
See all posts