WEARING seat belts on coaches is compulsory, but virtually unenforceable, police admitted last night.
Passengers aged over 14 are responsible for wearing their belts, which are now a feature of most coaches after being required in all new vehicles since 2001.
Coach operators must tell passengers that seat belts are a legal requirement, but this can be left to signs rather than announcements by drivers, and it is up to passengers to comply.
According to National Express policy, the driver of the coach involved in Wednesday night's crash would have told passengers to put on their belts.
Since last September, passengers not belting up have been liable for 30 fixed penalty fines, which can increase up to 500 if the case goes to court.
However, Strathclyde Police told The Scotsman that the law was difficult to enforce. A spokeswoman said passengers were required to wear belts only when a coach was moving, so officers could not pull over vehicles for spot checks and would have to travel on vehicles to be able to issue fines.
She was unable to say if any fines had been issued, because they were recorded with seat- belt offences by car drivers.
The Confederation of Passenger Transport, which represents bus firms, said it was unaware of any passengers being fined.
Dianne Ferreira, a spokeswoman for Brake, a UK road safety group, said coach passengers should wear seat belts at all times. She said: "It was made law a few months ago that coach passengers had to be strapped in, but I am not sure there is enough public awareness."
The Royal Society for the Prevention of Accidents said the potentially deadly effect of unrestrained coach passengers on people travelling with them was no different from that in a car. Advertising campaigns have starkly illustrated how people in the front seats of cars can be killed by rear-seat passengers being thrown forward.
Roger Vincent, its spokesman, said: "People without seat belts can kill other people, and I see no difference between coaches and cars in that respect."
The Department for Transport plans to launch a consultation shortly on regulations for passengers under 14.
Figures show coaches and buses remain the safest form of road travel in the UK, accounting for 17 deaths per one billion passenger kilometres travelled, compared to 37 for cars and 1,500 for motorcycles. Nine people were killed in coaches and buses - none in Scotland - in 2005, compared to 1,675 in cars.
However, a study presented to the United Nations Economic Commission for Europe in 2003 showed double-deckers were involved in a disproportionate number of crashes, and called for their stability to be increased.
Ras Hashemi, of the Cranfield Impact Centre in Bedfordshire, said: "The height makes them top heavy. They just topple over then skid along on their side."
Simon Posner, the CPT's director general, said: "Passengers now tend to treat coaches like planes and immediately belt up when they hear the seat belt announcement."
There are strict controls over coach drivers' hours. Coaches are fitted with tachographs, which record the time the driver started, vehicle speed, rest times and planned finishing time.