Controversial work to reduce a section of the A21 on the Kent/Sussex border to single carriageway has started.
The narrowed road was one of the A21's few bits of dual carriageway
The work to narrow the road at Flimwell started on Monday morning and is scheduled to last for six weeks.
The 1.6km stretch of road has seen 11 fatal crashes since 1999 and the Highways Agency says the work is being done for safety reasons.
But MPs have called for the whole A21 to be dualled and drivers have also criticised the narrowing of the road.
The A21 is the main road from London to Hastings on the south coast and the section at Flimwell is one of the few stretches of dual carriageway south of Tonbridge.
The road will be resurfaced as well as being reduced to a single lane.
The Highways Agency said the work was "designed to improve safety" by "preventing vehicles overtaking each other in a short space".
Plans for a bypass round Flimwell were published in February
Michael Foster, the MP for Hastings, and Archie Norman, who was MP for Tunbridge Wells until the recent election, have both called for more of the A21 to be widened, rather than it being narrowed.
And some motorists have criticised the decision to make the road single carriageway, saying it removes one of the A21's few opportunities to legally overtake slow moving vehicles such as heavy lorries.
But people living near the road at Flimwell have welcomed the changes, hoping it will reduce the number of serious accidents.
When the decision to narrow the road was announced last year, Valerie McGuaine from the A21 Action Group said: "We have waited four long years to arrive at this point and we have something to celebrate indeed.
"Unfortunately we have lost quite a lot of lives but hopefully in the future that is going to end."
Plans for a bypass which would take most of the A21's traffic away from Flimwell were announced in February.
Highways Agency figures show the road carries 18,500 vehicles a day through Flimwell, which is right on the border of Kent and East Sussex.