Narrowing Main Street to Make Room for Sidewalks

Residents of Main Street were surprised and disturbed to learn that the lanes will be narrowed to 11-12 feet to make room for the new sidewalks that have been proposed.  The narrowing is described as a “traffic calming” measure that will reduce speed. A representative of New Canaan’s police department notes that narrowing the lanes on Main Street should result in a 3 mph speed reduction.

Traffic Calming in New Canaan

According to the Police Commission Traffic Calming description on the Town’s website, “Traffic Calming measures are not to inappropriately delay emergency response to fires, medical or other emergencies. Certain streets and roads have been identified as emergency response routes where certain traffic calming devices that increase response times will not be considered.” Main Street is identified as an emergency response “collector road.” With narrow lanes bounded by curbed sidewalks, we wonder where other vehicles will be able to pull over when emergency response vehicles need to pass.

“Traffic calming must be neighborhood driven and it is necessary to keep residents informed,” the Police Commission site continues. “Residents of an area identified as possible installation sites must be given the opportunity to participate in the discussions leading to the implementation of such proposals.” Many residents of lower Main Street, who have observed the traffic patterns for years, have expressed their concern about the wisdom of narrowing this winding, hilly, heavily traveled road.

SWRPA – A Regional Study

In the late 1990’s the eight communities in Southwestern Connecticut commissioned a study of traffic calming measures.  A paper describing this SWRPA traffic calming project notes that “Roadway classification was found to be critical. Studies on most traffic calming devices have recommended that such devices are not appropriate on arterials and should be of limited use on collectors.” The full study, A Traffic Calming Toolbox, is available at the New Canaan Police Station.

ITE – Industry Standards

According to the Police Commission, “Traffic calming measures shall be designed to comply with recognized standards and practices of the Institute of Transportation Engineers, ASHET and the Connecticut Department of Transportation.” In 1999 the ITE published “Traffic Calming State of the Practice,” which found “minor” speed reduction for street narrowing.  The sample size of 7 road narrowings produced an average speed reduction of 2.6 mph, with a standard deviation of 5.5 (page 104). What does this mean? There’s not a strong correlation between street width reduction and speed. 

Most of the published studies on traffic calming have a large margin of error, offering weak confidence in the predictive value of their conclusions.

In fact, most of the available studies on street narrowing are documenting projects where the streets are straight and flat, often in towns where roads are laid out in a grid. Main Street is none of these. Narrowing is often accomplished by permitting on-street parking, or by drawing the outside lane lines closer to the center lane.

Among the disruptive trade-offs:

• Emergency response vehicles are delayed,
• Trucks, school buses and other large vehicles have a more difficult time navigating the roadway,
• Traffic impacts are shifted to other roads, and volume increases on side streets.

We question whether narrowing Main Street is wise. If the stated purpose is to lower the speed, why not start by reducing the speed limit?

Or are we about to build a permanently dangerous change into our Town’s infrastructure, inconvenience drivers, and slow passage of emergency vehicles in order to accommodate sidewalks?

Tags: collector road, emergency response, main street, New Canaan, safety, traffic calming