Improvements to the A6 between Finedon and Burton Latimer following three fatal accidents in one year will begin this week.
The stretch of road which has been classified as one of the county’s most dangerous after being designated as a red route, has been the scene of 27 collisions resulting in injuries in the past three years.
Three of the collisions have been fatal, claiming four lives, while seven more resulted in serious injuries.
Work – which is set to last two weeks – will begin on Monday, September 9, with hatchings being painted on the wider stretch of the road.
The speed limit between Finedon and the junction with Higham Road, Burton Latimer, will also be reduced from 60 mph.
The plans follow meetings between Northamptonshire County Council, the police and fire service.
Northamptonshire Highways road safety manager John Spencer said: “Through the continual daily analysis of collision data it quickly became apparent this route was becoming a cause for concern.
“It is now a red route and we are in the middle of a very detailed study of it.
“Detailed analysis of all of the incidents helps us to pinpoint trends, patterns and common causation factors.
“Over the three-mile stretch there can be many causation factors including dangerous overtaking, excess speed and drinking and driving. We look at all of those issues.
“Nothing is ruled in, and nothing is ruled out in terms of engineering, education and enforcement until the analysis process has concluded.
“We can then consider a menu of appropriate intervention measures.
“We looked at the whole stretch in detail, including the roundabout, straight section of road and bends just outside Finedon.
“We have undertaken a huge amount of analysis.”
Police are continuing to carry out speed enforcement operations along the route to try and clamp down on speeding drivers.
Northants Fire and Rescue personnel have also spent time in nearby towns to explain what the proposals will entail.