Work to remove the controversial M4 bus lane is due to begin.
The unpopular 3.5-mile (5.6km) lane on the London-bound carriageway near Heathrow Airport was introduced in 1999.
The Highways Agency said work starts on Monday night and traffic could begin using the whole lane later in the week.
It will be suspended for 18 months before coming back into use for the Olympics, after which it is likely to be scrapped for good.
Transport Secretary Philip Hammond said: "We will monitor the suspension over the next 18 months, but my intention is to scrap the lane permanently after the London 2012 Olympics are over."
Only buses, licensed black taxis and motorcycles, making up about 7% of London-bound traffic, can currently use the bus lane.
Work to remove and replace road signs and markings and create a revised road layout where the carriageway merges from three lanes to two, before the elevated section, will begin at 2200 GMT on Monday.
The M4 eastbound, between junctions two and three, will be closed overnight for four nights from Monday and again for four nights from 22 November. Diversions will be in place.
One lane of the M4 westbound, in the same place, will be shut for three nights from Monday to create a safety zone while work is carried out on the central reservation.
The Highways Agency said traffic could start using some of the extra lane as early as Tuesday morning and the entire project was likely to be completed by mid-December.
Mr Hammond said: "Scrapping the M4 bus lane is symbolic of this Government's decision to end the war on the motorist. It ends the injustice suffered by thousands of drivers who sit in traffic next to an empty lane day in day out."