America clamps down on highway monsters

After a decade in which they have steadily gained ascendancy on America's roads, the four-wheel drive suburban mega-cars known by the ugly acronym SUV - sports utility vehicle - are suddenly under attack. You name it, they are guilty of it: they are too big, too profligate, too expensive, but most of all, too dangerous.

Going by sporty names like Rodeo and Rava, they tend to be driven by a certain class and they may or may not have a flock of children on board. You see almost as many of them in Hampstead as in the Hamptons, and like as not your small, low, environmentally responsible car has been bullied by one recently.

The only difference between the two sides of the Atlantic is that over here the offending beasts are more numerous and bigger. Much bigger.

The difficulty until now has been to translate the complaints from common or garden car drivers into sound evidence. But now the clamour has grown to the point where the "interface" between cars and SUVs is to be tested. Starting yesterday, the National Highway Traffic Safety Administration (NHTSA) - the main road safety agency - is to conduct six crash tests to establish how cars fare in collisions with SUVs.

As so often in America, the first impetus for change came not from consumers - the complaints of car drivers went largely unheeded - but from the insurance companies. They found that they were paying out ever larger sums in compensation for death, injury and car damage after crashes in which a car was worsted by an SUV. The suspicion mounted that America's highways were becoming the scene of vastly unequal combat.

A series of studies has concluded that the size and weight of a vehicle has a big effect both on its capacity to protect the occupants in a crash and on "agressivity" - the harm it is likely to inflict on the occupants of the other vehicle. The latest such study, published this week by the University of Michigan's transportation research institute, says that when a car and an SUV collide head-on, fatalities are five times as high in cars as in SUVs. The ratio was lower - three to one - in crashes between cars and the all-American workhorse, the pick-up truck.

In other crashes, the ratio for fatalities was much higher - up to 30 to one where SUVs hit cars on the driver's side. The report called for urgent studies to improve the crash-worthiness of passenger cars and reduce the "aggressiveness" of SUVs.

For General Motors, the study was greeted more as a vindication of SUV safety than an indictment of cars. Such reassurance was particularly welcome because of criticism that the higher centre of gravity of SUVs could make them unstable at high speed. The increasing number of SUV-drivers also see little problem. If they want a bigger, heavier, safer car and are prepared to pay the higher price and fuel costs, why not? The anti-SUV coalition objects that SUVs are inherently dangerous to other road users.