The project will enable vehicles to travel on the hard shoulder at peak times. It includes installing overhead signage gantries as well as creating emergency laybys every 500m over 34km of motorway.
Speaking at NCE's "Maximising transport capacity" conference, Agency head of ATM David Grant said that it had drawn up a "healthy" list of preferred bidders to roll out ATM across sections of the M6, M42 and M40.
The success of the M42 ATM trial prompted transport secretary Ruth Kelly to allocate £150M of Transport Innovation Fund cash to extend ATM to the Birmingham motorway last October.
Grant said that following a rapid feasibility study this will be rolled out in five phases.
"ATM is proven to alleviate congestion (on the M42)," said Grant. "It is tried and tested to make best use of the available road space."
Phase 1 covers M6 junctions 4 to 5, M42 junctions 7 to 9 and M40 junctions 16 to 3/3a. Phase 2 is for the M6 junctions 8 to 10a. These will cost a total of £150M with £96M allocated for construction costs.
Grant added that phase 3 to install ATM on the elevated section of the M6 junctions 3 to 5 would follow. This will present huge challenges for engineers in terms of reliable traffic detection. More government funding will be needed for these phases.
He also said that testing was set to start next month on a section of the M42 ATM to increase hard shoulder running speeds from the current 50mph to 60mph, between junctions 3a and 4.