Police say the Second Severn Crossing has reopened westbound following a blockade by Kurdish protesters.
The protest caused the Severn Bridge to shut after demonstrators stopped their cars in the middle of the motorway.
Around 15 people stopped traffic and held up a Kurdish flag half way across the motorway bridge between England and Wales.
Eyewitnesses say the group were yelling anti-Turkish slogans. The demonstration started at 1.30pm and lasted for an hour.
Watch this eye-witness video taken from a vehicle passing the protest.
A police spokeswoman has said motorists were not impressed by the demonstration holding up traffic.
Police have yet to confirm if there have been any arrests and the roads are now clear.
Two lanes are blocked due to an overturned van on the M4 Second Severn Crossing westbound. That's between J22 for the M43 and 23 for the M48.
An 83-year old man has died after driving his car the wrong way along the M4 near the Second Severn Crossing.
At around 11pm last night, a Toyota Corolla was travelling westbound across the bridge.
Just before the toll booths the car turned around, and was travelling east on the wrong side of the carriageway.
It continued past junction 22 (M49) before colliding with two other vehicles.
The 83-year old driver of the Corolla died from his injuries. The other drivers weren't seriously hurt.
Police would like to speak to anyone who may have witnessed the incident to telephone the Collision Investigation Unit on 101.