Police are investigating the death of a man who was hit by a car on the M5 in Gloucestershire.

The motorway was initially shut in both directions after the incident, which happened at about 7.30am on Saturday. Two northbound lanes have since reopened, according to Highways England.

A spokesman for the roads agency said there were delays of about 15 minutes, but these were expected to worsen as late morning – peak time for weekend motorway driving – approached.

The incident occurred near junction 13 on the southbound side, Gloucestershire police said. “The man was declared dead at the scene. No one else was injured,” a spokesman said.

“The road remains closed between junction 12 and junction 14 southbound … while a serious collision investigation takes place. The southbound side is likely to remain closed for some time.”