Motorists are urged to be patient while the next phase of rumble lines, safety barriers and signs are rolled out on State Highway 8.
The work, taking place between Cromwell and Clyde, is being carried out by the NZ Transport Agency (NZTA) as part of the $22.5million nationwide safety boost programme.
The programme features a range of low-cost safety improvements to make 30 regional state highways safer.
A short section of SH8, which was reduced to 30kmh last week, was down to one lane while some of the work took place.
NZTA system manager Graeme Hall said the programme aimed to make effective safety improvements on rural highways.
Rumble strips gave distracted drivers a “wake-up call” if they strayed across the line, he said.
The strips could reduce crashes by about 25% and fatal run-off-road crashes by up to 42%.
Improved signage was being placed on the road side to warn drivers of risks ahead, including winding sections of road and sharp curves.
Safety barriers were also part of the programme to stop vehicles before they hit something, such as a tree or a power pole, harder, he said.
The first phase of the programme, which started on SH8 in February, focused on rumble strips.
Further improvements will be put in place throughout the remainder of the year.
“We expect work on this highway to be completed by late 2018.
“We appreciate your patience and co-operation while this work is under way. The improvements will help prevent people and members of your community from being killed or seriously injured on this stretch of road.
“We ask all drivers to be patient when leaving an area of temporary low speed, for everyone’s safety.”