The Outer Truck Limits

Sydney Morning Herald

Thursday May 16, 1996

Bill McKinnon

Semis and coaches exceed the 90 km/h heavy vehicle restriction easily and often. Bill McKinnon investigates.

On NSW roads, "100 Speed Limited" signs on heavy vehicles have the same status as bumper stickers. Stemming from the 1988 Grafton and Kempsey tragedies which took 55 lives, the limits were intended to lower coach and semi-trailer speeds - but have ironically allowed these vehicles to travel legally faster.

Speed limiters restrict a vehicle's maximum speed to 100 km/h by electronic or mechanical means and are compulsory on most NSW registered heavy vehicles manufactured after January 1, 1988, or optional on vehicles built before this date.

According to police, a 4 km/h tolerance is permitted, so a speed limited truck or coach displaying signs on the front and back can travel at up to 104 km/h on most stretches of highway, 14 km/h faster than the maximum legal speed for heavy vehicles without speed limiters.

It is an offence to display a speed limited sign on a pre-1988 heavy vehicle which has no speed limiter fitted - but any operator can purchase a sign without producing evidence that the truck or coach is speed limited. Walk into a truck stop on a major highway, and a "100 Speed Limited" sign is yours for $10-$15, no questions asked.

"If a truck is displaying the signs, it can travel at up to 104 km/h on the open road and there's nothing we can do," a senior NSW police source told Drive. "We can't tear the engine apart to prove whether a limiter is fitted, and neither can the Roads and Traffic Authority."

Another officer said: "Relatively few trucks travel at very high speeds these days. The majority of operators and drivers do the right thing but there are still some cowboys. We caught one doing 147 km/h, and he had a 100 Speed Limited sign on the back. On steep downhill runs some speed limiters can't hold a truck to the legal speed, and if the driver wants to go faster still, he can shift into neutral.

"When we catch a truck doing more than 104 km/h on a flat stretch of highway, and it's displaying 'Speed Limited' signs, the first thing the driver usually says is 'I've got a speed limiter but it's faulty'. We have to take his word for it.

"If he wants to avoid a defect notice, he can tell us there's no speed limiter fitted, and receive a $635 fine for unlawfully displaying the sign.

"We suspect some operators fit an on/off switch to the speed limiter, but again we can't check."

Terry Dean, the commercial director of the NSW Road Transport Association, defends the current speed limiter regulations. "The law says a truck must have a speed limiter fitted if it is displaying the signs. The majority of operators who purchase signs have speed limiters fitted to their trucks. There are a few cowboys who don't obey the regulations."

The RTA could sharpen the teeth of its speed limiter regulation by a) controlling the issue of "100 Speed Limited" signs, b) requiring the operator to prove his vehicle is fitted with a speed limiter before the signs are issued, verifying this at each annual inspection, and c) making signs applicable to one prime mover or coach only.

A spokesperson said, "There is not enough evidence of trucks speeding in 100 limit areas to warrant [our] controlling the issue of signs."