Definition of Active traffic management

Active Traffic Management (ATM) is a new motorway scheme on the M42 motorway south-east of Birmingham in England. ATM incorporates a number of features such as variable speed limits to aid traffic flow and regular gantry-mounted speed cameras to ensure the speed limits are followed. These are hooked up to the UK's own  ANPR (Automatic Number Plate Recognition) network which can then be used to store movements, check tax and insurance, e.t.c.