Traffic calming demonstrations produce promising data


Traffic calming demonstrations produce promising data

Tags: , ,

In fall of 2015, the Missouri Chapter of the American Planning Association collaborated with Trailnet, the HEAL Partnership, the City of St. Louis, and community residents to host four pop-up traffic calming demonstrations within the City of St. Louis. The demonstrations showcased proven methods of slowing traffic and increasing safety with traffic calming designs. The Missouri Chapter of the American Planning Association, Trailnet and the HEAL Partnership used these demonstrations to educate community members, elected officials, and city staff on how we can work together to create safer and more pleasant streets.

IMG_8279Like most U.S. cities, the St. Louis designed its streets to prioritize people driving, making our city less pleasant and less safe for people on foot. In the U.S., 12 percent of fatal traffic crashes involve people walking; however, in St. Louis that figure is 36 percent. Last year, 19 pedestrians were killed in the City of St. Louis. In fact, more pedestrians were killed in 2015 than in 2013 and 2014 combined. These sobering statistics earned St. Louis a designation as a Focus City by the National Highway Traffic Safety Administration, joining 16 other U.S. cities in which pedestrian and bicycle deaths are higher than the national average.

These crashes are a consequence of streets designed to accommodate streetcars and high levels of traffic. For example, some residential streets in St. Louis are as wide as 65 feet, which is wide enough for five highway lanes. This encourages excessive speeding and puts people that walk in danger. Moreover, high-traffic, high-speed roads create impassable boundaries that effectively turn neighborhoods into “islands” for people walking. For households that do not have any cars, high stress roads limit access to important amenities, such as parks and schools. Pedestrian safety is a growing concern in St. Louis, and traffic calming can help solve this problem by slowing down vehicles and prioritizing safe and pleasant streets over moving traffic.

At the pop-up traffic calming demonstrations in the neighborhoods of Dutchtown, Carondelet, JeffVanderLou and the Ville, colorful tires, cones and plants were used to narrow traffic lanes, add roundabouts, create medians, extend sidewalks, and highlight crosswalks. In each neighborhood, speed guns were used to collect speed data; trained volunteers observed and tallied vehicular stops as “completely  stopped,” “rolling stop, or “no stop” and Trailnet surveyed residents of the neighborhood on their perceptions of the street’s safety and accessibility. Data was collected during the demonstrations as well as on non-demonstration days to help understand how traffic calming impacted the neighborhoods.


With traffic calming measures in place, cars drove slower, came to more complete stops, and were less likely to roll through stop signs. Residents expressed that their local streets felt safer and more pleasant. During the traffic calming demonstrations, residents said it was easier to cross the street since it was more likely cars would obey stop signs and follow the speed limit. In most neighborhoods, the survey results indicated the traffic calming demonstrations improved residents’ perceptions of the street’s safety, and most residents expressed that the demonstrations made their street feel more pleasant.

Trailnet looked at average differences in response taken during demonstrations as well as without a demonstration in place. In most neighborhoods, the survey analysis showed the demonstrations results were positive in regards of safety. 

The only exception was in the Dutchtown neighborhood (Gasconade Street between Compton Avenue and Minnesota Avenue). While some of the survey results in Dutchtown were negative, the survey analysis suggests that these differences might have been random occurrences. These results can be partly explained by the fact that some residents were hesitant with certain aspects of the Dutchtown demonstration. For example, some residents felt they weren’t well enough informed about the traffic calming demonstrations and were upset to have parking spaces were removed from the street. also, some residents were hesitant about one of the proposed traffic calming designs; the chicane, which causes drivers to swerve slightly.  Residents feared the design would turn Gasconade Street into a one-way street. In reality, this feature maintains a two-way street with enough space to have two cars pass each other.


Overall, in all four neighborhoods, average vehicle speed fell nearly 7 mph with the traffic calming demonstrations in place. When pedestrian crashes do occur, slower vehicle speeds result in fewer pedestrian deaths.

Screen Shot 2016-03-02 at 11.26.27 PMThe Ville demonstration (St. Louis Avenue between Sarah Street and Whittier Street)  was especially successful with the average vehicle speed falling nearly 13 mph and the number of complete stops during the demonstration increasing from 34 percent to 65 percent. The demonstration site was served by four bus stops, so the increased stops helped people to get to their buses safely throughout the day.

Because of the success of these events, Trailnet is making the resources from these demonstrations available for free to any organization or St. Louis neighborhood wanting to create a similar demonstration in their community. For information on accessing these materials, contact Grace Kyung at grace@trailnet.org or 314-436-1324 ext. 110.

To see the full results from these demonstrations see the infographic below.

Traffic Calming Infographic Version 5

Traffic Calming Infographic