Motorists can expect to travel at an average of just 15mph on the M5 this afternoon (December 16) as the Christmas getaway begins.Today is expected to be the busiest day on the roads across the UK with the peak chaos at around 4pm because Christmas traffic is combining with the Friday rush hour.A planned strike on the Southern network may also lead to higher numbers of vehicles taking to the roads.According to data from Inrix, the M5 between junctions 14 at Thornbury and junctions 21 at...
