Expect traffic delays on Nelson's main arterial route Rocks Rd over the next month as work resumes on stabilising the cliff face.
Traffic lanes will be narrowed and cyclists will have to merge with traffic, the NZ Transport Agency warns.
The speed limit will also be reduced to 30kmh for safety.
Nelson Tasman acting highways manager Mark Owen acknowledged it would be a bit of pain.
"Ultimately, a few delays are a small price to pay for a safer, more secure road."
NZTA has carried out regular inspections of the cliff face, and identified the need for maintenance and repair works to the existing section of rockfall protection netting, he said.
A section of the State Highway 6 route will be reduced to a narrower traffic lane in each direction so barriers and debris screens can be installed to protect road users from falling rocks.
"It's really important that motorists take extra care and hang back to ensure cyclists can merge safely," Owen said.
"To keep everyone safe, we're putting in force a speed limit of 30kmh, and it's crucial that everyone observes it," he said.
There would also be brief closures at times to enable access to the site, but these would be scheduled for off-peak periods to minimise traffic delays.
The work would be carried out during the daytime seven days a week, as weather conditions permitted.
Further work on other sections of the cliff face was being planned and was expected to be completed later this year.
Routine maintenance work is also being carried out on the Rocks Rd seawall to patch damaged concrete.
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