Part of the M65 on the border of Hyndburn and Blackburn was closed following a collision between a lorry and a mobile crane.
The vehicles, travelling east towards Burnley, collided near junction 5 of the motorway shortly after 11am yesterday.
A 44-year-old man who was driving the lorry sustained serious injuries and remains in hospital.
Officers from Lancashire's police motorway unit were called to the scene and the road was closed for more than an hour.
Works were carried out to repair the central reservation barrier on the motorway stretch.
A spokesman from Lancashire police said: "At 11.15am a heavy goods vehicle collided with the rear of a mobile crane which weighed approximately 60 tonnes. The lorry driver sustained serious injuries and is still in hospital."