There is stop-start traffic on much of the M5 northbound due to holiday traffic, with multiple crashes also causing further delays.
There are also patches of heavy traffic on much of the M5 northbound, with the worst-hit area between J26 (Wellington) and J21 (Weston-super-Mare).
There is also queuing traffic on the M5 southbound after a multi-vehicle crash near J19 for Portishead. One lane is closed with congestion now trailing back to J17 for Cribbs Causeway.
People getting onto the M5 in Devon are facing long queues due to a crash.
National Highways said: "There are delays of over 30 minutes on the A30 eastbound in Devon between Exeter and the M5 J31 due to an earlier collision which has just cleared.
"All lanes have re-opened however delays may take some time to clear. Please allow extra journey time."
M4 now clear
A multi-vehicle crash sparked 90-minute delays on the M4 eastbound between Wales and Bristol around lunchtime. The incident has now cleared and traffic has returned to normal.
Another crash further along the M4 eastbound, between J18 for Bath/Tormarton and J17 for Chippenham, has also cleared with traffic now flowing freely.