Filed under: Green, First Drive, UK
Speed bumps are bad for the planet
by Jonathon Ramsey on Jan 27th 2008 at 2:35PM 
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 speeding 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 speed cameras" 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]
Reader Comments (Page 1 of 3)
SOhp101 2:44PM (1/27/2008)
How about putting in those speed bumps that are really low and wide, so that traveling 25 mph on them isn't too bad but going any faster means you'll mess up your suspension?
The ones that are shown in the picture are horrid... you have to be going
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Andrew 6:52PM (1/27/2008)
Imagine the benefits of driverless cars. The car would be able to travel virtually everywhere without stops.
SOhp101 2:45PM (1/27/2008)
err i guess you can't use any less than symbols...
... less than 5mph and still you'll feel like you're offroading.
Speed cameras of ANY sort are the devil--the only thing they're good at is increasing revenues for the company that makes them and the city that sponsors them.
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FSM 2:50PM (1/27/2008)
All speed bumbs do is cause people to speed between them rather than over them.
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icu812ru469 3:03PM (1/27/2008)
Manufacturers just need to make suspensions for vehicles to withstand a 40mph drive by over these things and everything is solved... :p
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naggs 3:05PM (1/27/2008)
well duh
everyone has is on the gas brake gas brake
how much did they waste on that study?
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idave101 3:09PM (1/27/2008)
58mpg? What would happen when you put a fat ass Suburban through this same test? 4mpg?
31mpg is a dream for most Americans.
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Guenther 8:02PM (1/27/2008)
Nothing- ya just thump over the bump.
vintage 3:12PM (1/27/2008)
Here's an idea. Keep your snot-nosed brats off the streets, and raise the speed limit to 75mph. I think it'd help Darwin out too.
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Seoultrain 3:18PM (1/27/2008)
I wonder what the calc would look like on unneeded stopsigns. With those thousands of cars wasting their momentum to heat, then having to speed up again...
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Polly Prissy Pants 8:58PM (1/27/2008)
There are entire industries built around creating these types of problems. Check out 'Traffic Calming' and all the idiots who think it's good that you do nothing but accelerate and brake every 100 yards. Eliminating traffic calming and installing smart, optimized traffic lights alone would probably cut our countries oil usage by 20%.
J.Crew 3:23PM (1/27/2008)
Generally these speed bumps are added in areas where safety is the major concern. The number of areas where speed bumps are in use is very limited so I doubt the worlds ecosystem can take a small hit where safety takes priority - like around schools and shopping centers.
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vintage 3:38PM (1/27/2008)
Actually they generally pop up near really suburban homes with overprotective parents who think that people going 30mph in a 25 are making personal threats on their child's lives, and then bitch to the city council a whole lot until the city spends thousands of dollars putting in speed bumps near their houses. Ask me how I know.
naggs 3:59PM (1/27/2008)
you know how to fight back?
every time you go over a speed bump, honk your horn
some shiny happy people in La Jolla, CA who live on a major street got speed bumps put in. after a few weeks of near constant honking at all hours of the day and night, they were begging the city council to remove them.
tell your kids to stay out of the damn street and the earth won't need to take another "small" hit.
btw, global warming is nothing but a series of "small hits" is turning you light on a small hit? what if billion of lightbulbs are turned on for 20 hours a day? are you raping the earth on your daily commute? what if billions of people are doing it? global warming is the result of everyone doing what they need to do to get thru the day. even the oil/power/consumer goods companies are simply responding to market forces to do what companies do, make money.
at what point are we going to decide that we can no longer justify another small hit to prevent a few dozen deaths a year? where do we draw the line?
J.Crew 4:39PM (1/27/2008)
Thanks Al Gore - I guess we should try and do nothing every day. Literally, do nothing. Don't move, don't turn on lights, and don't get out of bed. I would also feel bad if I set the alarm clock as it is going to raise the earths temp when it goes off in the morning. In that way I would not show up to work on time and get fired. I would then tell my employer that I am saving the planet because I refused to set the alarm clock. I am sure they would understand. Even if that does not happen my job would likely be shipped to China where the environment laws are way more lax and they pollute more per day than we do in a week based on their population alone.
Ok, back to reality...
In all honesty I hope we are all trying to recycle, use energy efficient bulbs, keep the heat low, and buy the most fuel efficient vehicles possible based on the use required for the vehicle. My point was I only see these speed bumps around schools and shopping centers for safety reasons which make sense. Anything we do will effect the environment and this is one cost I see being reasonable. These speed bumps should not be on residential streets outside of these safety areas, and if they are then I feel bad for the residents in the area because that disrupts the flow of traffic for no reason and now they are proven to do environmental damage to boot.
geo.stewart 5:02PM (1/27/2008)
yes, because all those people doing 35 in a 20 or 25 for a 1/2 mile of neighborhood road really need that extra 30 seconds.
or else, its a long neighborhood road that is being used as a cut-through.
I'm sorry, I've never seen them used on a main road. I think they are irritating but I see the point and I'm more irritated at the idiots who race through a residential area that make them necessary.
vintage 7:30PM (1/27/2008)
Geo Stewart:
Going 35 in a 25 is not dangerous if you are paying attention. You are being a crybaby.
geo.stewart 3:31PM (1/27/2008)
I like the comment about going 30 vs 20 being more economical. I'm sure they tested that with just one vehicle also, as that is dependent on the car's gearing which we all know varies by car. Anyone who has owned an econobox has gotten behind someone driving in their sweetspot which just happens to be the point where you are revving high but shifting has you revving too low.
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BMWdownshift 3:36PM (1/27/2008)
Speed cameras
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Steve B. 3:48PM (1/27/2008)
I wonder the same thing about four way stops, and California's fetish for them. In newer developed areas, they seem to use 4-way stops as a speed control measure. If these were replaced by roundabouts, it would improve traffic flow, reduce emissions, fuel consumption, at the detriment of local coffers (stop-sign enforcement and such).
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