Minibuses and lorries may be legally required to slow down on motorways if the Government passes plans to "create a level playing field" across the industry.
The Department for Transport (DfT) has proposed lowering the maximum motorway speed limit from 70mph to 60mph for lorries under 7.5 tonnes, and banning them from the outside lane.
Limits would drop from 70mph to 65mph for minibuses and smaller buses and coaches, while those longer than 12 metres could go faster, with their motorway limits raised from 60mph to 65mph.
Paul Clark, road safety minister, said the changes were being proposed "to provide clarity for everybody - drivers, operators, other motorists and the police - as well as making sure that there is a level playing field for those operating in the bus, coach and road haulage industry."
According to DfT statement to MPs, the differences between new vehicles fitted with speed limiters, and older ones which are not, means firms have less incentive to invest in safer new vehicles.
Although new lorries can only reach 56mph, and buses and coaches with more than eight seats are limited to 62.5mph, older vehicles are still able to drive at 70mph on the motorway.
© Press Association 2009