Fewer drivers were punished for using mobile phones last year in England and Wales, police figures suggest.
The number of drivers given penalty points for using a mobile device at the wheel fell by 24% in 2014 and by more than 40% from 2010-14.
The figures, which were obtained from a Freedom of Information Act request by BBC Radio 5 live show, showed that 72,753 fixed penalty notices (FPN) were given out in 2014.
Information was requested from the 43 police forces in England and Wales, plus British Transport Police - and 36 provided it.
In 2013, 95,941 FPNs were given out for mobile phone offences, while 122,752 were given out in 2010 by the same forces.
However, an earlier study from the Department for Transport (DfT) showed 1.1% of drivers in England and Scotland were observed holding a phone in their hand, with a further 0.5% observed holding the phone to their ear.
That equates to potentially more than 470,000 motorists and this survey also showed no improvement in those breaking the law since it was last repeated in 2009.
The IAM has long stated the reduction in visible policing meant drivers are flouting the law in larger numbers – and there is no reason to think the trend won’t get worse, it said.
Neil Greig, IAM director of policy and research, said: “If 470,000 motorists are using mobile phones illegally and 72,000 tickets and 99,000 courses are being processed; it is a tiny and disappointing response.
“More worryingly neither approach seems to be having any effect on the numbers observed breaking the law.
“Most are still getting away with it. Until the fear of being caught increases we will continue to see drivers taking risks holding mobile devices while driving.”
One force, Staffordshire Police, issued just four fixed penalty notices for mobile phone use last year.
The force told the BBC it had developed its own programme to deal with motorists - a four-hour "crash course" run by police, fire and victim support officials.
By comparison, the Metropolitan Police issued the most FPNs - 22,729 - last year, while Thames Valley Police issued 10,579 - the second highest.
Drivers caught using mobile phones at the wheel can be given a fixed penalty notice - which means three penalty points and a £100 fine.