The highway was closed due to landslides at Seri and Ramban areas in the district, Superintendent of Police, Ramban Anil Magotra said.
Hundreds of vehicles were stranded on the 300-km-long highway, the only road linking Kashmir Valley with the rest of the country, due the closure.
Personnel of the Border Roads Organisation cleared the landslides and the highway was reopened for traffic after four hours, Magotra said.