(1888PressRelease)
February 11, 2007 - To use fuel efficiently, the driver of a heavy vehicle needs to store the energy contained in the vehicle. Traffic calming is perhaps the greatest waste of fuel ever devised. One new roundabout, causing an average speed reduction of 30 Kph, traversed five times loaded at 32.5 tonnes, and four times at 11.5 tonnes, used on average 2 gallons extra fuel per day.
This can be proved by mathematical calculation, but I have never seen the equations in any text book. I have undertaken a rough calculation of the extra fuel used by causing a heavy vehicle to stop or slow. The roundabout calculation shows that fuel consumption is doubled over a certain road section from the start of braking, to the end of acceleration. This will be true for all vehicles forced to stop or slow. The same principle applies to all vehicles if the stored energy has to be wasted through the brakes.
Miles per Gallon is not a true measure of fuel consumption. The true measure is grams per kilowatt hour, as used by transport engine manufacturers. The total amount of time under power is the factor which determines Mpg. Almost all internal combustion engines are most efficient at or near full load. This is because the heat lost through cooling and the exhaust is almost constant under any load condition.
" The Transport Research Laboratory conducted emission testing on roads with 75 metre hump spacing and found with vehicles travelling at a constant speed, CO emissions increased by 70-80%, Hydro-carbons by 70-100% and CO2 by 50-60%. It is obvious that the percentages would have increased by many times over had the more realistic scenario of braking and accelerating for humps been tested as well, but the realistic pollution figures would have designated every humps scheme as a serious danger to residents’ health. "
Air pollution could be reduced by reversing the present theory of traffic management by traffic calming. In many cases this would cost very little as it mainly involves altering the phasing of traffic lights. The replacement of all small diameter roundabouts on major roads would also produce a useful reduction in emissions from all vehicles. Part time traffic signals and "free give way" left turns could replace many current roundabouts and other permanently controlled junctions, without a significant reduction in safety. Speed warning signs as opposed to speed camera's could also play a beneficial roll, likewise the latest flashing cats eyes which could be used to warn drivers when part time signals are operating.
It is now ten years since I wrote the basis for the above and since then very little policy has changed at least nationally here in the UK. However, it would appear that future policy is now to be focused on reducing transport's negative effect on the environment, It is quite ironic that the Green's actually campaigned for the introduction of traffic calming, even after I sent Friends of the Earth and others letters pointing out the extra pollution it caused. There is also strong evidence to suggest that traffic calming in an area leads to an increase in asthma cases, the same is probably true for 20 Mph zones. I can only hope that concern for the environment will put an end to traffic calming once and for all. The road safety high priests will all squeal like stuck pigs but it has to be pointed out that most of them have never campaigned for annual eye-sight tests for drivers. It is estimated that 20% of drivers in the UK fail to meet the eye-sight requirements, and they are probably responsible for 50% of the serious accidents. A new roundabout was installed at a cross-roads on one of my local roads after two serious accidents in two weeks. I know for a fact that the driver involved in both as the cause was practically blind at the time of the accidents, I knew his grand-daughter well.
To reduce transport's effect on Global Warming many speed limits need to be increased not cut further. When 90 Kph EU speed limiters were introduced on HGV's during the 1990s fuel consumption on local 38 tonne vehicles doing night runs from Lancashire to Scotland increased from 9 Mpg to 7 Mpg. Higher speeds will be no problem if all drivers have decent eye-sight which is regularly tested. The only problem is will the UK government manage to wean itself off fuel tax revenues. I believe that casualties have been cut by 15% in the Borough of Barnet since they ripped out existing traffic calming, casualties for cyclists dropped by twice the London average. You have only got to watch Road Wars on Sky Three to see that traffic calming is worse than useless when it comes to stopping or even slowing determined reckless drivers. It would appear that lack of funds for essential road maintenance caused by using the roads budget for traffic calming has killed at least one moped rider, despite Tameside council's attempt to avoid responsibility. Increased transport pollution of the type generated by traffic calming has also recently been shown to stunt lung development in children.
The recent chaos on the roads during relatively light snow may be due in part to traffic calming being installed on some hills.
