Up to three-quarters of all urban drivers in Ireland could be exceeding the speed limits just because they're in the wrong gear - and thereby increasing their risk of attracting penalty points.
According to the Institute of Advanced Motorists (IAM), the optimum gear for the average car in urban areas is third. But some 60 per cent of respondents to a survey in Britain in December said they typically use fourth or fifth gear while driving in built-up areas.
Figures published last October by a working group set up by the Government to study speed limits claimed that almost a quarter of all cars exceed speed limits. This was supported by the Dublin Cycling Campaign which claims the average speed of traffic in 30 mph suburban zones is actually closer to 40 mph.
Modern cars can 'creep' up speed in such circumstances, while keeping them in third gear lessens the likelihood. This seems at odds with the original training most motorists receive, advising them to move quickly up through the gears to achieve better fuel economy and lower emissions from their vehicle.
The IAM's national training manager for Ireland, Michael Kavanagh, says that, while no similar survey has been carried out here, it would be reasonable to assume a similar situation exists on Irish roads.
But he added that the flexibility of reaction to changing circumstances must always override other considerations, and being in the correct gear at a given speed is essential to maintain this flexibility.
"In a higher gear than the conditions demand, there is that tendency for the speed to creep up a bit," he says. "But what is even more important is that if the driver presses down or lifts off the accelerator, something happens immediately. The principle is that if I come across a hazard, the gear I'm in should provide instant acceleration or deceleration, whichever is appropriate to the situation, and if I'm in third gear at 30 mph, then I'm obviously going to have that flexibility."
AA Ireland's spokesman Conor Faughnan says that many of the 'perverse' speed limits on urban roads exacerbate the problem because of local conditions.
"The 40 mph Belfield overpass on the Stillorgan Road is typical, where you are coming into a dip. And then there's the 30 mph Dundrum pypass where you not only have to be in third gear, but have your foot on the brake to stay within the speed limit while going downhill."
He says there are lots of locations where 'unnaturally low' speed limits make it difficult for motorists to adhere to the limits and at the same time drive smoothly. "It is an urban minefield out there in speed limits terms, but it is something we're going to have to live with for the future with the planned increase in the numbers of speed cameras."
As to the problem of increased emissions and fuel consumption from driving in lower gears increases emissions and fuel consumption, Mr Faughnan points out that, as urban car use is already 'hopelessly inefficient' anyway, changing driving techniques to avoid creeping over the limits wouldn't make an appreciable difference to overall emissions.
Over 80,000 motorists nationally have received penalty points for speeding since the system was introduced at the end of 2002. The Garda Press Office says no current individual breakdown of urban/national penalties for speeding are available.