The M5 is currently closed in both directions at Junction 21 in Weston due to a police incident.
Severe delays on the approach has caused seven miles of congestion southbound and around five miles northbound.
As motorists aim to avoid the traffic, there are also delays on the A370 approaching Congresbury.
A spokesperson for Avon and Somerset Police said: "We closed the road earlier today due to concerns for the welfare of a pedestrian.
"There are no reported injuries.
"We are awaiting confirmation the road will be reopened shortly."
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules here