Traffic Calming is the use of a road's structure to slow traffic. Traffic calming strategies are based on years of data showing that drivers respond more consistently to the appearance of a road than to speed limit signs. In car-pedestrian impacts, speeds of 20mph or less dramatically reduce the chance of fatality. At 40 mph, the chance of fatality verges on 90%. At 20 mph, the chance of fatality is below 15%. In general, these numbers also likely apply to cyclists, so traffic-calming in a general sense benefits bicyclists as well, with some possible exceptions (see below).
The basic principle of traffic calming is to force drivers to use their judgment to slow down to negotiate visible road obstacles. One can add curves to a straight road, narrow the roadway (with neck-downs or bump-outs, or simply narrowing the apparent roadway with a shoulder-stripe) raise sections of roadway (with speed tables or humps or raised crosswalks), add visible markers to pedestrian crossings (signage in the roadway, changes in pavement texture, pedestrian-activated signals), install roundabouts at intersections, or change angled intersections to right-angle intersections.
Newton apparently banned speed humps in 1999, because of the fire department's concern that speed humps would damage or slow down rescue vehicles [need verification]. It is unclear whether there is any actual cause for concern, such as a demonstrated history of such problems in communities with speed humps. [Need more research on this point.]
Clint Schuckel, Newton's traffic engineer, subscribes to the wisdom of traffic-calming, and has been installing traffic-calming devices around Newton. Some examples:
- Bulb-out/right-angle intersection at Jackson St. and Daniel St. (under testing in '08-'09) near Bowen School
- Closing of angled access road at Walnut St. and Watertown St. to make a right-angle only turn
- Raised crosswalk on Woodland Road (installed because of an outcry after the death of a pedestrian)
- Series of bump-outs on Fuller St. near Chestnut St.
Some residents near the Jackson/Daniel bump-out have signed a petition to halt it, though the project will go ahead, according to the Newton TAB, if testing confirms its success. [4/30/09 Update: I've received an email from Victoria Danberg and Dan Parker saying that construction will start soon.]
Bicyclists also sometimes object to some traffic calming measures, especially bump-outs, since they run the risk of forcing bicyclists into traffic. A number of bikers have found the bump-outs on Fuller St. a problem. An alternative view is to think of a bump-out as a permanently parked car that can't "door" you. There are also techniques for engineering bump-outs to make them negotiable for bikes. Newton's road's department should be encouraged to explore these options.
Many of Newton's main roads could use some traffic calming of some kind; drivers rarely drive as low as the posted speed limits. Example: Parker Street between Cypress and Route 9. Driving from Newton Center toward route 9, from the crest of the hill to Route 9 there is only one visible impediment to the downhill straightaway: a crosswalk. Much of the year, the crosswalk itself is obscured by salt and sand, and the movable crosswalk sign is missing. The crossing guard stationed there morning and afternoon for students walking to and from the Bowen School regularly sees cars go through the intersection at high speed, ignoring her signals, or screeching to a stop. If the only apparent impediment to a driver is one crosswalk on a long, straight downhill slope, the likelihood of an accident is high, especially with commuting drivers intent on a destination. A series of bump-outs, raised or textured crosswalks, narrowed travel lanes, or other calming devices on that downhill slope would reduce speeds and raise drivers' awareness of the potential for pedestrians.
Discuss Traffic Calming