Highways England says it will take a while for traffic to get back to normal.
The M5 has now reopened in both directions between junction 22 Burnham-on-Sea and junction 23 Bridgwater, after being closed earlier because of problems with overhead power lines.
But Highways England says there is still severe congestion in the area as traffic gets back to nomal.
Shortly after 11.00 today (Saturday, June 29) Highways England announced the closure and diverted drivers via the A38. With many people travelling to the coast or the Glastonbury Festival, the motorway closure caused a lot of disruption.
Highways England announced that the M5 was fully open again at 1.10pm. But it advised drivers to check before they travel, and - in the hot weather - to carry plenty of water in case their journey is delayed.
Further incident information is available from the Highways England website and the regional Twitter feed @HighwaysSWEST
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