MPs have said that a fall in the number of motoring offences being recorded could be due to lower numbers of traffic officers.
The Transport Select Committee has warned that further cuts to police forces could stop even more offences from being detected and recorded. It comes after the number of road policing officers fell from 7,104 to 4,356 between 2005 and 2014 in England and Wales.
Labour MP Louise Ellman, who chairs the Transport Select Committee, told the BBC: "The fall in overall road offences does not reflect an improvement in driving."
The number of offences detected on English and Welsh roads has fallen dramatically, going from 4.3 million in 2004 to 1.5 million in 2014.
This drop occurred despite the number of offences resulting in a fatality staying the same.
Pete Williams, RAC spokesman, said: "The sharp decline in roads policing officers appears to be having the very unwelcome effect of leading to fewer people being caught for illegal activity."
A report published by the Committee said that the drop in the amount of officers patrolling roads could be attributed to the increased use of technology. It said: "For enforcement to be successful and for educational campaigns to be convincing there must be the likelihood that offenders will be apprehended.