Motorists spent up to an hour of their Christmas morning stranded on the M1 after a three-car crash caused tailbacks.
The collision happened at around 9.20am near junction eight for Hemel Hempstead, Hertfordshire.
Police attended the scene but no-one was injured, according to Highways England.
Drivers posted pictures of the clogged roads on social media, showing scores of cars at a standstill across several lanes.
Radio host Edward Adoo wrote on Twitter: "Avoid M1 Northbound from Watford at all costs. Been here for an hour."
Delays peaked at around one hour, Highways England said, with an alternative junction opened to ease traffic.
The road was running again from 12.20pm, the agency added.