Radar detectors that warn motorists they are approaching speed cameras could be banned under proposals going before Parliament.
The detectors distinguish between working cameras and decoys
A ban, if passed in the Road Safety Bill, could come into force next year.
The devices, used by thousands of motorists, emit a warning sound when approaching a camera which is working.
They cost around £200 and fix on to car dashboards. Manufacturers say they improve safety by warning drivers of speed limits.
The detectors also alert motorists to mobile speed traps run by police.
The Road Safety Bill is aimed at meeting targets to reduce road deaths.
It also proposes flexible speeding fines which would distinguish between those travelling a couple of miles over the speed limit in a non-residential area away from schools and other dangers, and those travelling at high speeds or in sensitive areas.
The penalty for using a mobile phone could increase from £30 to £60 and three licence endorsement points under the bill.
It would also allow courts to force the worst drink-drivers to retake their driving tests.
Other measures include clear guidance on how fast emergency vehicles can travel, more retraining courses for bad drivers and allowing police better use of motor insurance information.
Ministers want to cut the number of people killed or seriously injured in road accidents by 40%, and by half for children, by 2010.
The government says it is half way towards meeting the targets, which are based on the average for the years 1994 to 1998.
But it says more progress is needed; in 2003, 3,508 people were killed and 33,707 seriously injured on Britain's roads.