The New Zealand Transport Agency is spending $2.5 million to install 18.5km of guardrails on State Highway One between Blenheim and Picton.
Marlborough Roads highway manager Frank Porter said everyone who drives the road would benefit from the project, which was designed to make the stretch of road safer.
"Guardrails are an affordable, relatively straightforward way to reduce the severity of crashes along this stretch of SH1," Mr Porter said.
"Over the past five years, we've seen 17 serious or fatal accidents here, and we want to bring that number down."
Up to 9000 vehicles drove between Blenheim and Picton every day and despite the guardrails making the roads and roadsides safer, Mr Porter said everybody had a part to play in bringing the road toll down.
"Along with safer roads and roadsides, safer speeds, safer vehicles, and safer use of the transport network make a real difference to preventing fatal and serious accidents on our roads."
The contract for the job was given to Higgins Contractors, who began working on September 16, and were expected to complete it by April 2014.
Mr Porter thanked drivers in advance and asked that they drive to the conditions and take care throughout the project.
"While we always do our best to do our work with as little disruption as possible, we know that roadworks almost always cause some inconvenience. Thank you for your patience and understanding while we do this important work to keep you safe."
- The Marlborough Express