Traffic Calming

Transportation is a service that contributes substantially to the well being of our economies. Personal mobility, whether by bicycle, car, bus or aircraft, occupies a significant part of almost every citizen’s day. And virtually all household goods—furniture, food, appliances and clothing—are the result of often complex chains of supply, production and distribution in which transportation plays a critical part.
The resource requirements and byproducts of transportation also pose sobering environmental challenges for society. Landscape, noise, energy dependence, air and water quality, and perhaps even global climate are all profoundly affected by society’s choices about transportation. The safety and security of the transportation system is also tremendously important to quality of life and economic efficiency.
Traditionally, streets were designed to include sidewalks with sharp, relatively square corners, a canopy of trees planted fairly close together in the terrace between the curb and sidewalk, and slightly narrower streets than those we typically build today. In contrast, post-WWII streets have tended toward wider streets with rounder corners at intersections and other features that give the motorist a sense of relatively greater space. Originally driven by a concern with motorist safety, all of these features have effectively raised what engineers call the design speed on many of our streets. Ironically, these higher design speeds can often lead to literally higher driving speeds that then prompt neighborhood residents to complain to their local governments about the need for more police enforcement, stop signs, and traffic signals.
The response in the U.S. is a version of traffic calming that was practiced as early as the late 1960s and early 1970s in such places as Berkeley, CA, Seattle, WA and Eugene, OR. The first national study of traffic calming was completed circa 1980. It explored residential preferences related to traffic, collected performance data on speed humps, and reviewed legal issues. Almost 20 years later, with a track record in place, the Federal Highway Administration (FHWA) funded another study in 1998 which led to the ITE report, Traffic Calming: State of the Practice, by Reid Ewing. As compared to the 1980 study, this report goes beyond residential streets to major thoroughfares, beyond speed humps to a toolbox of calming measures, and beyond legal issues to policy, procedural, and political challenges.
Nationally, police departments are quick to point out that the typical methods of constant speed limit enforcement can be a prohibitively expensive proposition and, regardless, often fail to reduce average speeds except for those times when the enforcement is conspicuously present. Similarly, as traffic engineers often tell us, stop signs and signals can increase congestion and, perhaps surprisingly, an intersections accident rate, including injuries to pedestrians. The general intent of traffic calming is to make the motorists aware that they are traveling through areas where there are potential conflicts with pedestrians and bicyclist and to encourage them to drive through the area respectfully.
To address these issues, cities have employed the observable relationship between street designs, motorist’s perceptions, and vehicular speed to generate a toolbox of street elements designed to calm traffic. Definitions of traffic calming vary, but they all share the goal of reducing vehicle speeds, improving safety, and enhancing quality of life. Some include all three "Es," traffic education, enforcement, and engineering. Most definitions focus on engineering measures to change driver behavior. Some focus on engineering measures that compel drivers to slow down, excluding those that use barriers to divert traffic. This include such traditional strategies as sharper corner radii as well as newer approaches, including chicanes, traffic circles, and corners that bulb out slightly into an intersection to shorten crosswalks.
Given the complexities of the factors that create unsafe road conditions and the fact that compliance rates to traffic laws are very low when unaccompanied by suitable designs, there is a need for investments in designs that resolve these problems. Researchers, practitioners, and community activists in Europe, Canada, and the United States after conducting before and after studies for the past two decades, have concurred in the success of traffic-calming designs in mitigating these problems. On the surface, the costs for retrofitting these designs may seem quite high, but a deeper analysis shows that the benefits accrued by these designs far outweigh the costs. Additionally, accidents caused by unsafe roads could lead to filing of expensive law suits.
The choker and pillars installed on E. Lake Street are designed to take a dangerous mid-block crosswalk and improve its safety through a design that encourages drivers to respect the rights of pedestrians. If the right of way is only for motorist, then the choker should be removed. If the right of way is for multiple forms of transportation, the choker and pillars are doing their job. The driver is identifying a hazard that requires them to slow down, all the time, and makes this intersection safer for pedestrians. They would be required to slow down for the pedestrians by law, but we know they rarely do. Now they are slowing down for the choker and pillars and the result is that the pedestrians are safer.