Mike Stevens | Nov 30, 2008

Researchers at Purdue University, in Indiana USA, have done a study into motorists' attitudes towards posted speed limits. In results sure to make the front page of Bleedin' Obvious Weekly, the researchers found that the majority of drivers have no problem breaking a posted speed limit by a small margin, and see no risk in doing so.

The university conducted a study of just under 1000 motorists and found that few people actually believe that the 'speed limit' figure signposted on roads is an 'absolute limit'. They consider it more a guideline.

The study found 21 percent of motorists think it's perfectly safe to exceed the speed limit by 5 mph (8 km/h). Another 43 percent saw no risk in going 10 mph over (16 km/h) over, and 36 percent reckoned it was ok to drive 20 mph (32 km/h) over the speed limit.

The cause, in America at least, is attributed in part to legislation introduced during the 'first oil shock' of the 1970s that reduced highway speed limits across the country to reduce America's fuel use and dependence on imported oil. Telling people then that speed limits were not safety-related, but to serve another purpose, resulted in a disconnect.

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It is compounded because road engineers (and regulators) set artificially low speed limits on roads. And everyone knows it. Paradoxically, regulators set the limits artifically low because they know that a percentage of people will continue to drive above the posted 'limit' if they feel they can get away with it. The limits also lazily relect the fact that conditions on a road can vary; with changing traffic 'loads', weather conditions, light and other variables.

How many times have you been all-but alone on a freeway in perfect driving conditions yet forced to travel at the same posted limit as when in bumper to bumper traffic?

And here's the problem: few drivers actually believe that all speed limits relate to 'safety', and not to something else - like an opportunity to collect revenue from speed cameras.

Australian drivers, like their American counterparts, have a casual attitude towards minor speeding. This 'low level civil disobedience' has got to the point where the NSW government is reportedly soon to reduce the demerit points penalty on low level speeding (exceeding the speed limit by 0-15km/hr), taking it down from three points. (Something they had increased only a few years ago.)

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To my thinking, the fact that many of our modern, smooth, straight, wide, video monitored, motorways have a speed limit which is under some of our old crumbling highways is what, in my mind, creates the biggest speed/safety disconnect.

Why are Sydney's M2 and M7, both created within the past ten years and still as smooth as a baby's backside, set with a speed limit of 100 km/h when the crusty old F3 connecting Sydney and Newcastle has a speed limit of 110 km/h? (Anyone commuting on the F3 needs to see a physio at least once a week.) In Victoria, the Hume freeway is now set at 110 km/h, but when opened in the '80s had a more-sensible 120 km/h limit. The extension to the Monash freeway to Warragul is set at 100 km/h, but so are narrow broken-shouldered bush back-roads.

And don't try telling me that dawdling along at a mind-numbing 110 km/h is safer than travelling at 120 or 130 km/h on the long freeway sections of an intercapital drive.

The 'speed limit' system needs to be completely overhauled. Freeway speeds should be increased, and metropolitan speeds should be applied more consistently and discerningly.

[ Wired ]

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