Roads made slick by rain — and drivers failing to adapt to slippery conditions — contributed to a spate of crashes across Northland yesterday.
One of the worst incidents occurred on State Highway 1 north of Okaihau, leaving a motorcyclist with serious limb injuries.
The rider was heading south about 7.40am when he lost control on the bend just after Rangiahua Bridge.
Okaihau fire chief Andrew Graham said the rider suffered a badly broken arm and appeared to be concussed.
''He was in a bad way,'' Graham said.
The Northland Rescue Helicopter was unable to land at the site due to dense fog in the valley so the rider, believed to be in his 30s, was taken to Okaihau by ambulance where firefighters set up a landing zone at the rugby club.
He was then flown to Whangārei Hospital.
The road was wet at the time.
More weather-related crashes followed around 9am on SH1, near Moerewa's Turntable Hill, and about 9.20am on Wiroa Rd, west of Kerikeri.
Later, around 10.10am, a ute and a car carrying a family of four came to grief on SH1 south of Whangārei, about 1km from the Maungakaramea turnoff.
In that case the ute ended up on its side next to the highway while the car, which had been heading south, spun around and came to rest in a ditch on the other side of the road. No one was badly hurt. Again the road was slick with rain at the time of the crash.
Senior Sergeant Ian Row, one of Northland's top traffic cops, said oil built up in road bitumen during long dry spells came to the surface in the first heavy rain.
''It's nothing new, we should all expect it and drive accordingly.''
Row said he did not expect drivers to crawl any time it rained after extended dry weather, simply to moderate their speed by a few kilometres per hour.
''Even 1-2km/h can be the difference between you making it around a corner, or not.''
He also urged Northlanders to drive defensively, for example by increasing following distances or keeping an eye out of pools of water which could make the car lose traction and crash.
Earlier, on Saturday afternoon, another motorcyclist was seriously injured after coming off his bike on Matauri Link Rd, off SH10 near the Matauri Bay turnoff. It is not known if weather was a factor in that crash.