Traffic calming truly has become an issue of international significance. It has been a focus of debate in the United States, Australia, Canada, and many European countries. Transportation professionals from several countries discussed their approach to traffic calming in the July 1997 issue of the ITE Journal.

AUSTRALIA

Ray Brindle looked at the development of traffic calming in Australia in his article "Traffic Calming in Australia--More than Neighborhood Traffic Management." In the 1960s and early 1970s, the traffic management focus in Australia was on "removing non-local traffic, thus affecting traffic flows in local streets." "Mixed success" with this approach prompted a new look at traffic management.

The prevailing European practice involved altering streets for both "visual and safety reasons" by reducing vehicle speeds and increasing efforts at streetscaping. Australia recently refocused its efforts on reducing vehicle speeds, and that focus remains the current neighborhood traffic management (NTM) practice. However, the general Australian approach to NTM has been far from unified. Instead it has been "patchy" at best--a "routine local government activity" in some areas and "still a novelty" in others. Some transportation professionals have also hesitated to make NTM more uniform, feeling a national standard would "restrict innovation and good practice."

Brindle noted that traffic calming has increased both the opportunities and "strategies" for reducing the effects of traffic in urban areas. The original intent of traffic calming--to reduce vehicle speeds on local streets--has been expanded to include "city-wide traffic reduction" and "even manipulation of the landuse-transport system." He emphasized that "if this broader vision of traffic calming is adopted, it is best seen as a concept (or objective) which underlies management policies for streets, traffic and the landuse-transport system to create more livable streets and urban areas." Brindle further emphasized that traffic calming, like road safety, is an "end" rather than a "means." Much of the current confusion and contradiction about the meaning of traffic calming might result because it is frequently viewed as a means to an end, while in actuality, traffic calming is an end in itself.

A group of Australian practitioners met to remedy traffic calming's lack of a unified definition. Their efforts involved three levels of traffic calming. Level I focused on local traffic calming; Level II focused on traffic routes; and Level III focused on the "city-wide" effects of traffic calming. They felt the distinctions among the three levels were significant enough to warrant creating a "traffic calming matrix" that would distinguish between those traffic calming "actions that concern engineering techniques and the physical environment, and those that imply social and cultural change."

This "wider view" of traffic management has a number of implications. Resistance to change "even [as] modest as speed control measures" has been significant. As a result, effecting change in "the wider interpretations of traffic calming . . . is likely to be even harder." Brindle indicated that the acceptance of these more radical changes requires "cultural change." The wider view of traffic calming has also improved efforts at Level II traffic calming, where the distinctions between residential streets and other traffic routes are often not clear. Moreover, the wider concept of traffic calming has been useful at the citywide level, where efforts must "shift" from traffic control techniques to efforts at "social change." The traffic calming matrix also provides for future developments in transportation: the so-called "car-free future" where streets should be designed for people rather than vehicles; educational programs that convince drivers "to drive less and drive differently"; and technological advances to control speed, which may function as both "an enforcement tool and a mechanism for behavior change."

Whatever the future of traffic calming in Australia, its goal of cultural change cannot occur "through traffic engineering alone." Rather, traffic calming "in its ultimate form . . . requires widespread and fundamental changes in the community's attitudes to urban development, travel mode and how they behave as drivers."

CANADA

The transportation profession in Canada has also struggled with the lack of a concrete definition for traffic calming. In response to this lack and to traffic calming's increasing popularity, the Transportation Association of Canada (TAC) and the Canadian Institute of Transportation Engineers (CITE) joined forces to create "Project 208." Their goal was "to develop a national, bilingual Guide to Neighborhood Traffic Calming." Mike Skene, Gene Chartier, Diane Erickson, Gary Mack, and Richard Drdul discussed Project 208 in their article "Developing a Canadian Guide to Traffic Calming."

Canadian transportation professionals have used traffic calming information based primarily on U.S. and European practices. However, besides being sketchy and contradictory, this information provided little on the "adverse impacts of traffic calming measures, such as increased noise, delay to emergency vehicles and effects on snow plowing and street cleaning operations." Canada has implemented traffic calming measures despite these information problems; however, lacking guidelines, these efforts have been largely inconsistent.

A 1993 national survey conducted by the City of Victoria, British Columbia revealed that more than 50 percent of the surveyed municipalities used stop signs as a traffic calming measure, but less than 20 percent had focused community involvement in traffic calming. In addition, less than 25 percent implemented traffic calming measures based on "accepted engineering guidelines." The majority (75 percent) carried out traffic calming in the face of community and political pressure.

Project 208 began in the fall of 1993 as a volunteer TAC project. In 1996 it became a multiple-source-funded project with the addition of CITE. Project 208's objectives included (1) guaranteeing a consistent application of traffic calming measures nationwide, (2) dissuading local approaches to traffic calming that might be ineffective or unsafe, and (3) persuading reluctant transportation professionals to use traffic calming. In addition, the project sought to examine traffic calming's negative impacts and liability issues.

Given that traffic calming can be a broad issue, the guide was purposely limited to residential streets, where most traffic problems are reported to take place. Each of the guide's four chapters will have a specific purpose. The introduction will cover three areas: an overview and definition of traffic calming, the guide's scope and purpose, and the liability and legal issues of traffic calming. The second chapter will focus on the importance of community involvement in traffic calming. The third chapter will classify the various devices associated with traffic calming, and the final chapter will discuss design guidelines for these devices. The guide will be illustrated with the use of technology, and it is hoped that CD versions will be available.

EUROPE

In his article "Traffic Calming in Europe," Klaus Schlabbach traced European traffic calming practices to their modest Dutch inception in 1970. By 1976, several other traffic calming speed-reduction practices had evolved, such that "a number of new traffic regulations came into effect and minimum design standards for residential precincts (woonerf) were published. . . ." Woonerfs were characterized by their inclusion of schools, offices, and recreational opportunities, as well as low traffic volumes. Traffic signs alone were judged "inadequate" for restricting speed, so other "physical measures" were required. Parking had to be fully considered and parking problems resolved, and future parking needs had to be anticipated and incorporated.

Other European countries followed suit and instituted traffic calming regulations, including Germany (1977), Denmark (1978), Austria (1983), and Switzerland (1984). In Germany, regulations were "supplemented" by signs creating "Traffic Restraint Precincts." These precincts were pedestrian-oriented and governed by rules that favored pedestrian use. In 1988 the Netherlands replaced the word "woonerf" with "erf" and abandoned the sign to recognize the "wider application" of traffic calming, incorporating shopping centers and other community areas.

Schlabbach noted that this "second generation of traffic calming schemes" was strengthened by both guidelines and legislation and could be further enhanced by informing and educating the public about traffic calming measures. These "social" attempts at traffic calming, where the public is actively interested and engaged, are as significant as the "physical" ones.

Studies of second-generation traffic calming methods have shown encouraging reductions in the number of injury crashes, based largely on reductions in speed and in the amount of vehicle traffic. The Netherlands has noted an injury-crash reduction of more than 80 percent. In Germany, the number of crashes went up to some degree, but "the number of casualties decreased (30 to 56 percent)." Great Britain (24 percent) and Austria (31 percent) have noted similar decreases in casualty numbers.