-> part of the pedestrian and bicycle information center
sitemap about us -> goes to pbic website links join email list ask us a question
  search     go to
community problems and solutions design and engineering digital library education and enforcement health and fitness insight transit research and development rails and trails policy and planning bicycle crashes news and events outreach and promotion

on-street facilities

shared use paths (trails)

signs and markings

traffic calming

bicycle parking


Traffic Calming

Twenty-five years ago, Dutch city planners began designing neighborhood streets in which it was practically impossible to drive a car at greater than walking pace; indeed, motor vehicle traffic was so unobtrusive that even though the streets had no raised sidewalks, people could walk, ride bikes, play, and even meet and converse with their neighbors without fear. The Dutch called these streets "woonerven" or "living yards". A woonerf usually featured a brick or paving block surface with speed humps, twists and turns, carefully managed parking, and a variety of other features designed to slow traffic down and discourage it from entering in the first place.

Gradually, the concept of woonerven spread to streets other than purely residential, and to other countries. The Germans adapted the idea and applied the phrase "traffic calming" to this kind of street design. They also began to develop 30 km/hr streets and zones that were not quite as radically altered as woonerven, but still slowed traffic down with physical changes such as chicanes, speed humps, speed tables, raised intersections, and mini-roundabouts or traffic circles.

In the late 1990's traffic calming began to become more widespread in United States communities. The Institute of Transportation Engineers and the Federal Highway Administration recently teamed up to develop a detailed state of the practice report on traffic calming in the US that documents the experience of 20 communities with a variety of traffic calming devices. In addition, they collected numerous resources on traffic calming, and developed a training course on the subject.

New Traffic Calming Website:

The Federal Highway Administration inaugurated a new Web site dedicated to all the known and/or electronically publicized transportation programs and studies that pertain to traffic calming.
go to site

The site provides:

The general objectives of traffic calming
Traffic calming measures
Traffic calming measures
Links to traffic calming programs
Direct links to other related agencies
A list of recent studies
A list of any upcoming events
An intake page for reader feedback and contact information

FHWA - Traffic Calming
ITE Traffic Calming Web Site

One issue that the FHWA/ITE report deals with only briefly is whether traffic calming benefits bicycling. Some bicyclists are concerned that the traditional techniques used to slow traffic down have a negative impact on them:

  • Street narrowings that tend to slow motorists can mean that motorists drive closer to bicyclists when passing them, or motorists may try to "beat" the cyclist to the narrower section of the road.

  • Speed humps and other devices that change the level of the roadway may be uncomfortable and inconvenient for bicyclists, and abrupt changes in level may even have the potential to throw a bicyclist.

In the ITE report, author Reid Ewing quotes from Boulder, Colorado bicyclists who opposed some traffic calming projects for these reasons.

Bolder Bicycle Communters
PTI, The Community Guide To Traffic Calming

Cyclists in the United Kingdom dealt with this issue in the late 1980s. The Cyclists Touring Club published a special report on cyclists and traffic calming which was generally supportive but warned of the dangers of poorly designed traffic calming techniques that could indeed make life harder for bicyclists.

Throughout the rest of Europe, however, there was widespread acceptance that traffic calming was a huge benefit to bicyclists. Clarke and Dornfeld (FHWA, 1994) concluded in a report written as part of the National Bicycling and Walking Study that "the experience from Europe clearly shows that bicycle use has been encouraged by traffic calming".

Summary: Traffic Calming, Auto Restricted Zones and Other Traffic Management Techniques. Case Study #19, National Bicycling and Walking Study.

  1. Well designed and implemented traffic calming measures can have a number of beneficial impacts for bicyclists and pedestrians. The reduced vehicle speeds associated with such projects can reduce both the severity and incidence of motor vehicle/ bicycle crashes and can make bicyclists feel more comfortable in traffic.

  2. In certain situations, traffic calming techniques may be used to reduce the number of motor vehicles traveling along particular streets, and can increase the number of bicyclists.

  3. Traffic calming techniques can be used to provide better roadway conditions for bicyclists by better defining the space available to each mode, by improving intersection design for nonmotorized users and by giving greater priority to their movement.

A paper to the 1993 Velo City conference in Nottingham, England, described how the application of a general 30 km/hr speed limit in the city of Graz, Austria was considered an essential element of bicycle promotion. Traffic crashes fell by 30 percent. Although crashes involving bicyclists rose by 2 percent, there was no increase in the number of bicyclists injured and a 40 percent decrease in the number of bicyclists seriously injured. In addition, there was a presumption that levels of bicycling had increased. And, bicyclists were the strongest supporters of the 30 km/hr measures, with 81 percent for the project.

David Davies, presenting at the 1999 Velo City conference in Graz, Austria, wrote that "traffic calming should benefit bicyclists in so far as it reduces motor vehicle speeds. Indeed, Hass Klau (1991) found that it was a more effective way of encouraging cycling than the creation of cycle routes."

In the US, design information that addresses the needs of bicyclists in the development of traffic calming measures can be found at:

Oregon DOT.

Cambridge, Mass.

© Copyright 2000  Pedestrian and Bicycle Information Center