USA Banner

Official US Government Icon

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure Site Icon

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

U.S. Department of Transportation U.S. Department of Transportation Icon United States Department of Transportation United States Department of Transportation
FHWA Highway Safety Programs

Des Moines, Iowa – Ingersoll Avenue

TEMPORARY ROAD DIET BECOMES PERMANENT

Objective Features Results
  • Calm traffic
  • Improve pedestrian and bicycle access
  • Enhance business environment
  • Transit route
  • Commercial businesses
  • Community concerns
  • 50 percent reduction in crashes
  • Majority favored keeping Road Diet

 

Illustration of the 2 mile segment of Ingersoll Ave. treated with a road diet.

Three images, the first two of the before and after road diet configurations. The before configuration was a four-lane roadway with onstreet parking in either direction. The after configuration is a road diet with a two-way left turn lane separating two travel lanes in each direction, dedicated bike lanes in each direction, and onstreet parking in each direction. The third image is a photo of a signalized intersection with a left turn lane in the before configuration. Photo: Iowa DOT.

BACKGROUND

In 2010, the City of Des Moines, decided to "try out" a Road Diet on 4-lane Ingersoll Avenue between Polk Boulevard and Martin Luther King Jr. Parkway for a trial period. The 2-mile long Road Diet was implemented primarily as a Context Sensitive Solution (CSS) project to enhance the business environment with traffic calming, improve pedestrian and bicycle access, and add landscaping.

We were critical of the Des Moines City Council for its decision to approve the restriping of Ingersoll Avenue to change it from four lanes to three lanes...On all accounts, we were wrong. Our concerns proved to be unwarranted.

Cityview, Central Iowa's Independent Weekly1

Carrying 11,000 to 17,000 vehicles per day and serving as a transit bus route, Ingersoll Avenue is primarily developed with small, locally owned retail stores and restaurants. After the completion of the Road Diet, the final cross section included a 3-lane roadway with parking and bicycle lanes in both directions. The city provided right-turn lanes at the signalized intersections by prohibiting parking prior to the traffic signal.

Aerial photo of the after road diet configuration on the approach to an intersection. Photo: Iowa DOT.

COMMUNITY CONCERNS

The community initially expressed concerns about a potential Road Diet, mostly centered on reducing traffic lanes to accommodate bicyclists. Critics were worried the Road Diet would cause more congestion, thereby encouraging motorists to avoid the area and hurting the businesses along Ingersoll. The community was also worried the change could result in an increase in crashes. The city's response was to offer a 6-month trial period for the Road Diet. If the public's concerns came to fruition, then the city would happily convert Ingersoll back to a 4-lane roadway.

RESULTS

Six months after the conversion, no major traffic problems had developed during the Ingersoll Avenue Road Diet. Although the Road Diet was not initially proposed and promoted as a safety improvement project, a simple before-and-after crash study revealed a 50 percent reduction in crashes.

Overall, traffic volumes did not decrease. In fact, there was a 5 percent increase in traffic from 11:00 AM to 1:00 PM, which suggests that motorists found the Ingersoll corridor to be more comfortable and inviting during their lunchtime.

The city conducted an online survey to gauge the public's view of the Road Diet after implementation. Although there remained some opposition, the results revealed that fewer people opposed the project after implementation than when the project was first proposed, and a majority favored keeping the Road Diet and felt the road was safer.

As a result of these findings, the Des Moines City Council voted to retain the Ingersoll Avenue Road Diet.

1 Editorial Page, "Our View: Road diet makes Ingersoll fit" Cityview, Central Iowa's Independent Weekly, November 18, 2010. Accessed March 17, 2015. Available at: http://dmcityview.com/2010/11/18/columns/ourview.html.