New sentencing powers aimed at deterring speeding drivers will come into force next week with the worst offenders facing big increases in fines.
From Monday, motorists who travel at excessively dangerous speeds, including those who exceed 100 mph on motorways, could be fined up to 175 per cent of their weekly income.
In addition to the new fines, they could also be banned from driving for 56 days and have six points added to their licence.
But while road safety charities have welcomed the move, there is concern that the fines will have little impact on behaviour because there are too few traffic officers on the roads to enforce them.
With police forces having to make millions of pounds worth of cuts, many have chosen to reduce the number of traffic patrols.
Figures show that between 2005 and 2014 the number of specialist road officers in England and Wales reduced from 7,104 to 4,356.
Last year a group of MPs warned that sharp falls in the number of recorded motoring offences was more likely to be down to the lack of patrols rather than an improvement in driving standards.
RAC road safety spokesman, Pete Williams, said: “We welcome the change in sentencing guidelines for gross speeders. Anyone who breaks the limit excessively is a danger to every other road user and is unnecessarily putting lives at risk.
“Hopefully, hitting these offenders harder in the pocket will make them think twice before doing it again in the future.
But he added: "Tougher penalties are only effective in changing behaviour or increasing compliance if drivers genuinely believe that they are likely to be caught and prosecuted for breaking the law.
"With a significantly reduced number of dedicated roads police officers you have to question whether increased fines alone will change the attitude of excessive speeders.”
Gary Rae, campaigns director for Brake, also said the increase in fines was long overdue, but said the government had to ensure the resources were available to enforce them.
He said: "I hope that magistrates ensure the new sentences are consistently applied. It is also vital that a new government look afresh at police resources and make traffic policing a national priority, so that speeding drivers know they will be caught and punished.”
The introduction of the new top rate fines has opened the government up to accusations that they are attempting to raise revenue through the scheme, with any cash going to the Treasury.
Roger Lawson of the Association of British Drivers said any extra revenue could help recoup some of the huge court costs involved in prosecuting motorists.
Meanwhile it has emerged that millions of motorists could be inadvertently speeding because they have been given wrong information by their sat navs.
More than half of drivers who took part in a survey by the price comparison firm, uSwitch, admitted they did not know the correct speed limits for single and dual carriageways.
A third also admitted that they rarely updated their sat navs, meaning they were likely to be given out of date information where roads were subject to variable speed limits.
Rod Jones, insurance expert at uSwitch.com, said: "We are officially a nation of sat nav junkies, but our addiction to technology is causing us to drive dangerously and risk large fines.
"While sat navs and smartphones are an incredibly useful tool for motorists, it is important to remember they are never a complete substitute for knowing the rules of the road."