The project, which would affect 31 miles of road between the A312 at Heathrow Airport and Theale, is estimated to cost £525m-£720m and would see the creation of a 'managed motorway'.
The Home Secretary said: "I strongly welcome the Government’s investment in transport infrastructure, which includes the plan to improve the M4 between Reading and Heathrow.
"This should help reduce congestion on this busy stretch of road, which is vital to local residents and businesses.
"I hope this will be another boost to local transport, alongside Crossrail, electrification of the Great Western train line, and the proposed new western rail link to Heathrow.”
The changes would see the introduction of a system of varied speed limits and allowing the use of the hard shoulder as a running lane during busy times.
The Highways Agency hopes to deliver the scheme after the next spending review period after 2015.
Top Ten Articles
The Met Office has issued a yellow alert for Windsor and Maidenhead, Slough and Wokingham, warning that rain moving eastwards across the south of the country may turn to snow in some places.