New road safety measures are set to be introduced along the stretch between Ynysddu and Wyllie this summer.
Reducing the speed limit from 60mph to 40mph along the B4251 is one of the measures that will be introduced.
The work will be carried out by Caerphilly County Borough Council.
In October last year, 23-year-old nurse Laurie Jones, from Pontllanfraith, was killed after an accident on the road.
She had been driving home from a shift at the University Hospital of Wales in Cardiff in the early hours of the morning when she crashed. Her car was later found in the nearby Sirhowy River.
Other works to improve safety on the road include erecting chevron signs at bends, adding solid white lines to restrict overtaking, and improving the surface of the road.
Vegetation will also be cleared to make signs more visible to motorists.
A review of the speed limit was held in 2017 in line with Welsh Government guidance, but it didn’t identify any changes that needed to be made.
However, after a number of accidents on the road, an independent consultant was commissioned by the council to undertake a safety study to help minimise the chances of future accidents.
Councillor Philippa Marsden, leader of the council and councillor for Ynysddu, said: “This site has been the scene of a number of tragic accidents over recent years and we are keen to do all we can to reduce the chance of further incidents in future.
“These key improvements will help reduce the speed of traffic along this strategic route and will improve highway safety for road users and pedestrians.
“This is yet another example of the council taking positive steps to improve the local highway network for the traveling public.”
The council is also considering marking out cycle lanes along the road as part of the safety measures, after benefiting from Welsh Government transport funding.
The council has said it will monitor the improvements to measure how effective they are.
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