The Institute of Transportation Engineers (ITE), the international association that represents traffic engineers, transportation planners and similar professionals who plan and design roads and neighborhoods, has defined traffic calming as the installation of measures designed "to reduce traffic speeds and/or cut-through volumes, in the interest of street safety, livability, and other public purposes."

Traffic calming is the installation of safety solutions such as radar speed signs or speed humps to slow or reduce traffic in order to enhance safety for pedestrians and motorists. Already used effectively in Europe for decades, traffic calming is becoming more and more popular in communities throughout North America. It is the most effective way to reduce speeding on residential streets, avoid traffic accidents and prevent fatalities. Traffic calming programs begin either with the vision of progressive municipalities, with the knowledge of traffic engineers or public works officials, or at the request of concerned residents.

Preventing accidents, improving life

The purpose of traffic calming is to make neighborhoods safer, more pleasant, and more livable. Reducing the speed and volume of traffic to acceptable levels helps to achieve these goals. Traffic calming reduces accidents, collisions, noise, vibration, pollution, and crime.

Over decades of use, traffic calming solutions have proven to reduce both the number and severity of pedestrian crashes. Traffic calming measures such as "Your Speed" radar signs and dynamic messaging radar speed signs alert drivers to the speed they are driving at while reminding them of the posted speed limit. They have been shown to exert positive changes in driver behavior even over an extended period of time. Physical solutions, such as speed tables or speed humps, compel drivers to slow down to speeds at which they are better able to react to unexpected situations such as a child darting across the street.

Slower cars do save lives

In the event that a crash does occur, lower speeds significantly lower the probability of a fatality or serious injury. Each 1 mph reduction in traffic speed reduces vehicle collisions by 5% and fatalities by more than 5%. A driver travelling at 40 mph who sees a pedestrian 100 feet ahead will be traveling 38 mph on impact. If a driver was instead driving at 25 mph, he would have enough time to stop before ever reaching the pedestrian. Slowing traffic saves lives. Traffic calming measures have been called "the only antidote for the malady of child pedestrian accidents." (Transportation Alternatives Magazine)

Solution types

In recent years traffic calming has become increasingly popular in North America. Radar speed signs are a versatile solution used in a variety of situations and environments such as residential streets, private communities, industrial settings, and military bases. Rubber traffic calming solutions are often used in place of asphalt speed humps or speed cushions as a more visible, easier to transport, and often cost-effective alternative. They are an aesthetically pleasing way to slow vehicles while the premolded shape encourages driver acceptance.

To learn more about traffic calming, visit the Wikipedia Traffic Calming page or the Institute of Transportation Engineers (ITE)'s traffic calming page. You can also learn more about specific calming measures at the Federal Highway Administration's traffic calming section.

European Beginnings

Traffic calming began in Europe in the late 1960’s. Frustrated by cut-through traffic rendering their streets unsafe, residents of the Dutch city of Delft turned their street into an obstacle course for motor vehicles and a safe haven for their children. This first traffic calming solution, called "living yards", or "Woonerven", slowed traffic and lessened volume with the placement of tables, benches, sand boxes, and parking bays extending into the streets. Woonerven were endorsed by the government nearly a decade later in 1976.

In the following years, the idea spread to other countries around the world. Regulations and laws were created to govern the dimensions and locations of the woonerf designs. By 1990, myriads of streets in countries such as Austria, Denmark, France, Germany, Israel, Japan, Sweden, and Switzerland were similarly calmed.

More versatile solutions

While effective for small low-volume streets, the woonerf designs slowed vehicles to 9 mph and were thus impractical for larger and more frequently traveled roads. The theory of employing physical measures to deter vehicle speed had already proven effective and experimentation began to conceive of similar ideas that would be less costly and more adaptable to larger streets. Two types of measures were considered in addition to Woonerven; diversions such as street closures or one-way streets and physical deterrents such as speed humps and similar traffic calming measures. These traffic calming measures were judged to be the most efficient and cost-effective of the three alternatives.

Citywide safety

The first citywide traffic calming programs began in the early 1980’s when both Norway and Denmark were confronted with the problem of intercity traffic speeding through small towns. Unable to afford the exorbitant cost of building bypasses around each town, the government installed traffic calming measures such as chicanes, roundabouts, chokers, and other physical measures throughout local streets. With the installation of these measures, there was a significant reduction in speeds, fewer accidents, and better air quality. Many other cities throughout Europe followed suit with programs of their own.

Arrival in the United States

While street closures and traffic diverters were used in the Unites States in the late 1940’s and early 1950’s, the first area-wide traffic calming planning was conducted by Seattle in the early 1970’s.

The first comprehensive project conducted by Seattle was the Stevens neighborhood demonstration, which tested the efficiency of traffic calming measures on a 12 square block area that was often used for cut-through routes. This early project illustrated several important factors critical for program success including testing measures before permanent implementation; assessing public support; conducting before and after studies of traffic impacts; studying the effect of solutions on traffic accidents; addressing concerns of emergency vehicles; and opting for the most conservative design to effectively meet the city’s needs.

Seattle’s revolutionary traffic calming planning was followed by the establishment of a citywide traffic management plan in Berkeley, CA in 1975.

Expanding the Options

More recently, cities began using interactive radar speed signs in addition to physical solutions such as speed humps. These signs show motorists the speed limit while displaying the speed they are driving at in brightly lit LEDs. Despite the fact that signs present information drivers already know and include no punitive response such as traffic tickets, they have been shown to be effective in changing driver behavior. They have been shown to not only limit negative behavior but to also encourage positive driving habits even over the course of several miles.

A case study in Garden Grove, CA in 2003 found that drivers slowed an average of 14% as a result of a radar sign. A study in West Valley City, UT found that the 85th percentile speed was reduced from 37 mph to 31-23 mph after the installation of a speed sign while a case study in Marietta, GA found that up to 70% of drivers slow down at these signs.

Studying traffic calming

The first national study of traffic calming was conducted in the United States in 1980 and reviewed residential preferences regarding traffic, collected performance data on speed humps, and discussed legal issues.

In 1998, the Federal Highway Administration (FHWA) funded a more comprehensive traffic calming study by the Institute of Traffic Engineers (ITE) entitled Traffic Calming: State of the Practice, which reviewed residential streets and major thoroughfares, a variety of calming measures, and policy, procedural, and political challenges.

This study was followed in 2004 by an article published in the ITE Journal called Traffic Calming Practice Revisited. The article assessed a matured traffic calming market by reviewing traffic calming practices in 21 jurisdictions, comparing results to the initial ITE report. The updated study found a growing number of traffic calming programs across the US, less controversy regarding programs, improved receptiveness and interest in traffic calming, and greater use of comprehensive toolboxes employing a variety of solutions and measures.

There are myriad benefits associated with traffic calming.

These include:

  • Improved neighborhood livability
  • Enhanced safety
  • Decreased noise and air pollution
  • Less through traffic
  • Prevention of crime
  • Uurban redevelopment
  • Improved property value
  • Slower speeds save lives

Enhanced safety is one of the most fundamental benefits of traffic calming and one of the primary reasons that programs are created. By reducing speed and decreasing traffic volume, the number and severity of vehicle crashes are significantly diminished. Cars traveling at slower speeds are less likely to hit a pedestrian or cyclist. When accidents do occur at slower speeds, the impact is considerably lessened. A report by the Insurance Corporation of British Columbia titled Safety Benefits of Traffic Calming summarized 43 international studies and found that collision frequencies in areas with traffic calming measures declined between 8-100% and never increased.

A study conducted by The American Journal of Public Health found that children living near traffic calming devices were 50% less likely to be hit and injured by an automobile in their neighborhood. Children living within one block of a device were even less likely to be struck by a vehicle. The study found an astounding 53-60% reduction in the odds of injury or death in neighborhoods with traffic calming measures.

Added benefits

In addition to improved safety, traffic calming solutions present numerous further benefits. Pollution decreases as traffic volume is lessened and safer roads lead more individuals to walk or cycle instead of driving. Traffic calming measures can reduce noise levels by 4-5 decibels or more. Solutions often result in calmer, more aesthetically pleasing streets, providing both financial and environmental benefit.

Neighborhood crime has been shown to decrease with the installment of traffic calming techniques as decreased accessibility deters potential thieves and criminals. One study in Dayton, OH found that crime was reduce by 25-50% when traffic calming was introduced.

Traffic calming measures additionally benefit neighborhoods by increasing the value of property. In areas with lower traffic volume and slower average speeds, streets are safer, causing homes to sell at a premium. Many housing developments now include traffic calming in the initial street design in response to its attractiveness to homebuyers.

Some eye-opening traffic calming statistics:

Most traffic fatalities occur during daylight hours, by motorists driving straight ahead, and in normal weather conditions. 


Road traffic crashes are one of the top 10 causes of death worldwide, claiming approximately 1,300,000 people each year.

World Health Organization 

Traffic accidents are the only one of the top ten causes of death that are self inflicted.

World Health Organization

Of all unintentional injury deaths among children 0-19 years old, car accidents were the leading cause of death.

CDC Child Injury Data 

Teen drivers ages 16-19 are nearly three times more likely to be in a fatal crash than older drivers.

Center for Disease Control 

50% of people who die on the roads are “vulnerable users,” ie pedestrians, cyclists, and motorcylists.

World Health Organization  

1 in 4 car accidents involves cell phone use.


At any given daylight moment in America, approximately 660,000 drivers are using cell phones or electronic devices.

NHTSA Driver Electronic Device Use 

Speed kills. Speeding contributes to a third of all fatal crashes.

NHTSA  Speeding Traffic Facts  

A pedestrian was killed every two hours and injured every 8 minutes in traffic crashes in 2014.

NHTSA Pedestrian Traffic Safety 

17% of traffic fatalities and 10% of traffic injuries were among the elderly, aged 65 and over.

NHTSA Older Population Traffic Safety 

Of children killed in traffic accidents in 2014, 72% were passengers, 20% were pedestrians, and 5% were bicyclists.

NHTSA Child Traffic Safety 

A study of 43 international traffic calming programs found that traffic calming solutions decreased traffic accidents by 8-100%

ITE Traffic Calming: State of the Practice  

Children who live within a block of a speed hump have significantly lower odds of being struck and injured by a vehicle in their neighborhoods.

American Journal of Public Health  

Traffic calming has proven far more effective in preventing child pedestrian injuries than road safety education, which has been "unable to exert meaningful changes in the behavior of children"

American Journal of Public Health  

Speed humps [and similar devices] were found to have a 53-60% reduction in the odds of injury or death among children struck by vehicles in their neighborhoods.

American Journal of Public Health 

Traffic calming reduces severity of childhood injuries in the event of collision and makes it easier for drivers to avoid accidents in the first place.

National Children’s Bureau 

Speed management offers the best prevention against injuries from traffic accidents.

American Journal of Public Health  

The faster a vehicle is traveling, the more damage is done to a struck pedestrian. 5% of pedestrians would be killed if struck by a vehicle traveling 20 mph, 40% at 30 mph, 80% at 40 mph, and nearly 100% at speeds over 50 mph.

NHTSA Vehicle Travel Speeds and Pedestrian Injuries  

Unintentional injuries, including road crashes, are among the top 10 leading causes of death.

CDC Leading Causes of Death

To see statistics on radar speed sign effectiveness, please visit our Effectiveness page.

Funding Resources

Applying for a traffic safety grant can help to fund your traffic calming solutions to protect your roads. There are three types of grants generally available for traffic safety programs: federal grants, state grants, and local government grants. Locating and applying for one of these grants may seem daunting, but can be accomplished with determination and persistence.

Local city managers and city or county officials often know of grant opportunities. You can visit the website of your state, city or county for information on available funding. Calling local officials can also help you find more information about locally available grants.
Below, please find links to assist you in obtaining funding for your traffic calming program.

Finding Funding

Safe Routes to School – Safe Routes to School is a federally funded program aimed at increasing the health of children by encouraging students to walk and bike to school. These funds are earmarked to reduce traffic and improve safety near primary and middle schools. Traffic Logix radar speed signs and interlocking rubber solutions have been used in numerous school zones funded by Safe Routes and are an ideal solution to keep streets near schools safe and encourage children to be more physically active.

Catalog of Federal Domestic Grants – The Catalog of Federal Domestic Assistance provides detailed program descriptions for thousands of Federal assistance programs. Search for relevant keywords and learn what Federal funding opportunities are available that can help fund your traffic calming program. New opportunities are listed often so check back if you don’t find what you’re looking for.

Community Oriented Policing Services Funding – COPS Funding opportunities are listed here from the US Department of Justice. These grants give local law enforcement the resources to serve their communities in new ways.

US Department of Justice Funding – This website lists Department of Justice funding opportunities. Some may be applicable or used toward traffic calming initiatives.

Government grants listing and application – is a fundamental resource for applying for federal funds. You can search for opportunities on this website as well as submit your grant proposal to most federal agencies.

Police One- Police One’s grant section helps keep Law Enforcement informed of grants to fund a variety of programs and product purchases.

Police Grants Help- provides comprehensive resources for searching for police grants, with a database of federal, state, local, and corporate grant opportunities.

Firefighters Grants- The US Fire Administration website lists financial assistance opportunities available for firefighters.

Guide to state and local government websites – There is often funding available on the state or local level. To find grant opportunities in your area, use this website to find your state government and search their site or contact your local representative to learn more about funding in your area.

Grant Writing Guides

Writing a grant proposal can be daunting. Here are some valuable resources to assist you in the grant writing process.