Britain's Automobile Association has found another bump in the road to environmental kindness: speed bumps and really low speed limits. They took a car that got 58-mpg running a constant 30-MPH, and ran it over speedbumps at the Millbrook Proving Ground, slowing down and
up for each bump. What they discovered was that mileage dropped to 31-mpg and carbon dioxide emissions went up. The findings correlate with those of the country's Transport Research Laboratory, which reported that "carbon monoxide emissions are increased by as much as 82% and nitrous oxide levels by 37% on roads with speed bumps."
The AA also found that setting the speed limit at 20-MPH instead of 30-MPH raised car emissions and consumption by 10-percent. Along with the speed bump results, these are intriguing findings, but in the real world, how long do you spend each day driving over speed bumps, and driving 20-MPH? The AA says that it knows speeds need to be kept down on residential roads to keep children safe, but thinks that "average
" would be more acceptable to the driving public. Based on the comments we get at Autoblog about speed cameras, we doubt it.
[Source: Channel 4]