On-the-spot fines to punish careless drivers
16 August 2013 Last updated at 19:38 BST
Drivers across Britain who hog lanes or tailgate can now be punished with on-the-spot police fines of up to £100, and be issued with three points.
Ministers say the move will make tackling problem motorists easier.
The AA said a third of drivers risked facing a fine.
Richard Westcott reports.