Bridge work and accidents on the Northway snarled traffic Tuesday, with the final lane opening just as the evening commute began. Work will continue overnight on the northbound lanes.

The Twin Bridges required emergency repairs to potholes in the bridge surface, closing southbound lanes during the day on Tuesday.

Two northbound lanes will be closed from 10 p.m. until shortly before the morning commute, state Department of Transportation spokesman Bryan Viggiani said.

The work became necessary after the recent mix of weather that brought snow, rain, warming and then freezing temperatures, he said.

"That exacerbated any potholes that were there in the first place," he said.

Earlier Tuesday, accidents clogged the Northway during the morning commute.

Two crashes were cleared on the southbound and northbound side of the highway.

A wreck on the southbound side of the highway occurred between Exit 8 and the Twin Bridges. According to DOT, that crash closed the right shoulder of the highway.

Another crash on the northbound side of the highway occurred near Exit 8A.

Signs on Tuesday alerted commuters to road work and urged them to change lanes before the road work began.

Viggiani said he did not believe that was a factor in the morning's accidents.

"I don't think the construction signage had anything to do with it," he said.

Trooper Mark Cepiel said driver inattention was a factor in some of the crashes, none of which caused serious injuries.

"I was caught in it myself as far as the gridlock," he said. "I would say that the secondary ones seemed to be a result of stop-and-go traffic and people not paying attention to the vehicle in front of them."