The M4 bus lane is due to be axed at the end of the year.
Transport secretary Philip Hammond is expected to announce the closure of the controversial 3.5-mile lane near Heathrow airport at next week's Conservative Party conference.
The lane will be suspended for 18 months between 24 December and July 2012 when it will be used during the 2012 Olympic Games.
After then, it is expected it will be scrapped permanently.
It will mean that all motorists will be able to drive the entire London-bound carriageway on the section of motorway between junctions three and two.
At present, it can only be used by buses, licensed black taxis and motorcycles.
Hammond is expected to say: “I can announce today that from the end of December until the Olympics the M4 bus lane will be suspended. And once the Olympics are over, my intention is to scrap it permanently.”
The lane was introduced in 1999 by former transport secretary John Prescott.