Provincial police are warning drivers to slow down after two separate rollovers closed lanes on both major highways near London.

A transport truck rollover closed the westbound lanes of the 401 at Iona Road west of London around 7 a.m. Police say the closure is expected to last about five hours.

A transport entered the centre median before rolling back onto the westbound lanes. Police say it was lucky the truck did not cross into the eastbound lanes as there are no concrete barriers there.

The driver suffered minor injuries in the crash. The transport dumped its load of metal debris all over the highway causing a time consuming clean up. Hundreds of vehicles were trapped as a result for two hours. Around 9 a.m. all stranded vehicles were removed.

Police say charges are pending.

Meanwhile a vehicle rollover left one westbound lane of the 402 closed near Colonel Talbot around the same time Thursday morning.

Police have not said if anyone was injured in that crash.