The following proposed resolution in on the agenda of the Northampton City Council for 9/18/08:
The City Council endorses the Northampton Traffic Calming Manual and directs the Transportation and Parking Commission to monitor the program’s implementation, efficacy, and public feedback and, as necessary, approve any future modifications needed to achieve the City of Northampton’s overall goal of improving the safety and liveability of our streets and neighbourhoods.
Here is the Traffic Calming Manual as prepared by Northampton’s Transportation and Parking Commission. You can also download it as a PDF. This other PDF from Iowa State has good graphical depictions of several common traffic calming techniques.
Based on a cursory search of the web, it appears that different traffic calming techniques can have dramatically different impacts on bicyclists and snow removal…
Selected Comments on The (Traffic) Calming Chicane at TreeHugger:
…Fine when they are properly signposted – however when they use non-illuminated bollards with faulty reflectors they can be death traps at night…
I am currently in my second apartment, with a traffic calming device in front of it. Both are tiny round abouts. We often hear the screeching of breaks, especially on Friday and Saturday nights, followed by thumps, as cars don’t see the badly illuminated round about, and run into it…
…this [chicanes] usually trims the amount of available lane for cyclists. This means that cyclists have to permanently merge with car traffic to traverse the road that has the chicanes…
In Atlanta, it’s illegal to ride on the sidewalk. The traffic calming is so miserable that a local bike advocacy group is constantly fighting it…
Narrower traffic lanes, wider sidewalks? Ok, but if you live where there is snow you’ll need the extra width to put the snow somewhere.. up on the sidewalk I guess. You also effectively block the entire road should their be a breakdown…
Diverters – These do work, we have some in Minneapolis, but they are basicaly long chicanes which can cause a total mess by blocking in traffic when things go wrong. May seem trivial to some, but try backing up a school bus in the winter for three winding blocks on a dark winter night because the road is blocked with a stalled car.
Bumps, Humps, Strips, Cushions, et al… become ice ramps, road debris, snow plow driver injuries, pot holes, and other such wonderful things after a couple years in a winter state. Nothing funnier than watching people stuck on a road full of speed bumps because the ice won’t let them get enough traction and they can’t get a run up on the bump…
I like what Sacramento and Berkeley do instead, where they have bicycle boulevards and streets with lots of undulations (like speed bumps but gentler on a cyclist) to keep traffic slow thru residential areas…
…usually [in Holland] there is a bypass for cyclists, so they do not have to go through to the chicane…
This was tried in Concord NH. First millions was spent on speed bumps then millions on speed tables (long drawn out speed bumps); the best solution by the way, because of bikers & snow removal. Then millions was spent on these stupid “chicanes”. DEATH TRAPS actually!!!! Nightmare because traffic is actually one lane, only one car can go through at a time. How do you enforce right of way? …Snow removal was a nightmare. One year later millions was spent on making the streets as they had been since the beginning of roads…. STUPID!!!! STUPID!!!! STUPID!!!
Traffic Logix (a commercial vendor)
For cities in the snow belt, the winter months can prevent installing traffic calming devices due to interference with snow plows. It can be difficult to plow snow over speed humps or cushions, and solutions can be dug up or destroyed by the plows. Traffic Logix offers a simple solution to this problem. All of our devices are simple to install and can be easily removed each winter and reinstalled in the spring. Our devices have been installed in cities across the Northeast where they are removed each year during the winter months. In cities that use asphalt solutions, snow plow damage often causes cities to have to recreate the devices each spring. This is a timely and costly process. The removable Traffic Logix solutions are a far more cost-effective and convenient solution. [See videos of experiments in Northampton with Traffic Logix devices.]
Some bicyclists are concerned that the traditional techniques used to slow traffic down have a negative impact on them:
- Street narrowings that tend to slow motorists can mean that motorists drive closer to bicyclists when passing them or try to “beat” the cyclist to the narrower section of the road.
- Speed humps and other devices that change the level of the roadway may be uncomfortable and inconvenient for bicyclists. Another problem with speed humps is that drivers may try to swerve around the edges to avoid the full impact of the hump, which encourages them to swerve into where the bicyclist is riding along the curb. This is a real problem with speed humps and bicycles.
In the ITE report Traffic Calming: State of the Practice, author Reid Ewing quotes from Boulder, Colorado bicyclists who opposed some traffic calming projects for these reasons.
Throughout the rest of Europe, however, there has been widespread acceptance that traffic calming can benefit bicyclists. Clarke and Dornfeld (FHWA, 1994) concluded in a report written as part of the National Bicycling and Walking Study that “the experience from Europe clearly shows that bicycle use has been encouraged by traffic calming”.
- Well designed and implemented traffic calming measures can have a number of beneficial impacts for bicyclists and pedestrians. The reduced vehicle speeds associated with such projects can reduce both the severity and incidence of motor vehicle/ bicycle crashes and can make bicyclists feel more comfortable in traffic.
- In certain situations, traffic calming techniques may be used to reduce the number of motor vehicles traveling along particular streets, and can increase the number of bicyclists.
- Traffic calming techniques can be used to provide better roadway conditions for bicyclists by better defining the space available to each mode, by improving intersection design for nonmotorized users and by giving greater priority to their movement.
Portland Suburb Successfully Staves Off Densification
Oak Grove is a suburb of Portland that started more than a century ago,
when the nation’s first interurban electric rail line connected
Portland with Oregon City. People began building large homes on large
lots along the rail line, and a community sprang up.
years, many of the lots have been broken up, but in some areas, as
here, they average more than a third of an acre in size and some are
more than an acre. This means the area has very low densities and, in
turn, not much automobile traffic.
Grove remains unincorporated and thus under the jurisdiction of
Clackamas County. In 1995, county planners came to the neighborhood and
said they wanted to rezone the area to make it easier to walk around
and ride bicycles. There are no sidewalks in the area, but because the
area is so low in density, people do not hesitate to walk or ride