Highways chiefs had wanted to shut the coast-bound carriageway of the A299 Thanet Way for four weeks, before closing the opposite side for the same length of time to reconstruct the road.
Gridlock caused by the closure of the route on Monday prompted campaigners to say residents had been given a taste of things to come ahead of the scheduled work next month.
And in the wake of their warnings, Kent County Council bosses have announced the reconstruction project has been postponed.
Officials will go ahead with plans to upgrade the lights in the Chestfield Tunnel, but stress a contraflow system will be in place to prevent drivers from flooding the surrounding roads.
Reacting to the news, Tankerton councillor Neil Baker told KentOnline: "We were frankly aghast when we saw the plans to close both the roads off.
"The contraflow will no doubt help reduce the impact of traffic on the Old Thanet Way, which is where most of the traffic would have otherwise gone, and help lessen the impact of the roadworks.
"The details are still to be firmed up and ironed out, but for now, we know the construction works are postponed.
“The reason the New Thanet Way was built is because the old one couldn’t handle the traffic, and that was before all the extra cars now and the changes which makes it less suitable.”
The county council originally wanted to close the route to Thanet-bound traffic for 24 hours a day between April 24 and May 26.
The side taking drivers towards London would then have been sealed off until June 30.
Officials said the closures will have allowed them to replace the lights in the Chestfield tunnel and carry out “deep carriageway reconstruction repairs” at the same time.
But after two crashes along the A299 on Monday morning brought the area to a standstill, Cllr Baker said motorists had been given “a real-world example of what might happen” next month.
One of the accidents tragically saw a woman in her 30s die when the blue Vauxhall Mokka she was driving hit roadside furniture on the London-bound carriageway.
While emergency services were at the scene, motorists were diverted for hours along the Old Thanet Way between Herne Bay and Whitstable.
Traffic was brought to a standstill, with surrounding routes such as Canterbury Road in Herne and Sea Street in Herne Bay also gridlocked.
Cllr Baker and three of his Conservative colleagues - Mark Dance, Rob Thomas and Dan Watkins - had been pushing for a contraflow system to be used while the planned work took place.
"We were frankly aghast when we saw the plans to close both the roads off..."
But in an email sent to the politicians, KCC's highways team confirmed: "The difficult decision was made to postpone the carriageway reconstruction.
"This enables the use of the existing contraflow crossing points in the immediate vicinity of the tunnel, which allows the lighting upgrade to go ahead.
"This adds significant cost to the project, but will reduce disruption to road users.
"The carriageway reconstruction will still need to go ahead at a future date, and we are investigating the possibility of installing additional crossing points in strategic locations along the A299 Thanet Way to facilitate this."