Warning - the M4 will be closed between J18&19 all weekend, affecting anyone trying to get to offer day events using that route fyi. There is a diversion in place but according to WIWIKAU it got get very busy indeed last time and an accident jammed up the diversion route, too.
nationalhighways.co.uk/our-roads/south-west/a432-badminton-road-bridge-crossing-the-m4/