A stretch of State Highway 1 in the Rangitīkei has been the scene of six crashes in the past seven days, with local police asking drivers to take extra care.
The section of road near the town of Utiku has been undergoing roadworks since November 3. The latest crash resulted in a person being critically injured.
Emergency services were called to the scene at 2.20am on Monday, after a car went off the road and rolled on to the train tracks.
The driver was taken to Whanganui Hospital. Once stable, he was transferred to Wellington Hospital and was discharged on Tuesday afternoon.
Just a few hours earlier on Sunday evening there were two separate crashes involving the same set of roadworks.
A car flipped on to its roof at 8.20pm and just 30 minutes later another driver lost control and crashed their vehicle.
Taihape Police Station's officer in charge Harry Hughes said drivers needed to respect the conditions.
"The road is currently set up for busy day-time traffic. Once it's night time, there are no lights.
"People are entering the town a bit blasé and once they do enter the town, it's too late."
Hughes said NZTA contractors had made improvements to the area, including extra information boards and signage.
"Roadworks are expected at this time of the year because of the great weather. Drive to the conditions and adhere to the signs."
According to the latest NZTA data from 2018, the stretch of road has average annual daily traffic (AADT) of 6420, with 23.7 per cent of those being heavy vehicles.
NZTA systems manager Ross I'Anson said the road works were part of the annual essential maintenance plan, with the work set to finish by Friday, November 27.
He said they had added signage further away from the works to give drivers an earlier warning about the unsealed road.
"It gets rolled at the end of the day but sometimes gravel can become loose."
Hughes said he expected road sealing to begin sometime this week, greatly reducing the risk to drivers.