Lengthy jams were reported on motorways and other key routes after an estimated four million drivers began the return from their long weekend break.
Holidaymakers leaving resorts in the West Country encountered an eight-mile crawl on the A30 through Devon and Cornwall.
The M5 was snarled up for 20 miles near Bridgwater and Weston-super-Mare in Somerset while a four-mile jam built up on the roads out of Pembrokeshire.
Tensions rose among Britons returning from Paris when the cross-Channel rail link suffered delays of more than an hour due to a border control system glitch.
Passengers at the French capital’s Gare du Nord station spoke of “nightmare” scenes.
Charlie Daffern, 36, from Cheltenham, added: “People were becoming very restless and some were panicking as they had flights to catch from Heathrow.
“The main problem was a lack of communication.”
There was also misery and anger for outbound tourists as staff shortages led to hold-ups at Luton and Manchester airports.
Train services were packed because of restricted timetables resulting from Network Rail repairs.