The speed humps debate

After the aforementioned neighborhood speed hump debate, I did a little research into the claims of speed hump opponents.  Apparently, every auto club in the country has a vaguely disguised anti-speed hump site. (Some oppose not only speed humps but the very idea of traffic calming.)

Much of what I found on those sites is nonsense. The claim that speed humps will significantly increase noise, for example, holds no water. (It is true for bumps, however.) The only legitimate study finding an increase in noise found it limited to streets with at least 20% truck traffic—which includes none of the residential blocks in PLG. (An unscientific study by this writer found exactly zero percent truck traffic on Maple I after 6 pm.)

However, concerns about increased auto emissions resulting from cars' extra braking and accelerating do have some support:

"The mean emission rates of CO, HC, NOx, and CO2 from petrol non-catalyst, petrol catalyst, and diesel cars increased by up to 60% following the introduction of traffic calming measures. However, it was estimated that the increased emission rates were unlikely to have resulted in poor local air quality."
(UK's Transport Research Laboratory, Report 482, 2001)

"Federal officials no longer want to pay for Portland's traffic-calming
measures on Stevens Avenue because air-quality tests show the speed bumps and
raised crosswalks actually are increasing smog."
(Portland Press Herald, August 18, 1998)

Neither study is definitive (the Portland study, for example, speaks of speed bumps, which would require more extreme braking and accelerating), but they do raise interesting questions. If PLGers are too concerned about the environmental impact of speed humps to approve them, there are a number of other traffic calming methods that may do the trick. I'd highly recommend checking out Transportation Alternatives' Traffic Calming primer to get ideas.

RELATED: Do-It-Yourself Speed Humps

Comments

[Thom Miller]

I am new to this area of interest and have been doing some research. I found this article to be helpful and properly punctuated with informative links. Since a keystone of my research efforts turns on "economical solutions to local trafic issues", I highly appreciated the Do-It-Yourself link. Very inspirational! Thanks