Motorway services and the Highway Code's rest break advice

The Highway Code recommends a break of at least 15 minutes after every 2 hours of driving, which is the default this planner uses. UK motorway service areas are spaced roughly every 25-30 miles by regulation, so on most motorway routes you are rarely more than 15 minutes from a services stop, unlike some rural single-carriageway routes where planning ahead matters more.

Smart motorways and variable speed limits

Several UK motorways (M25, M1, M6 among others) are "smart motorways" with variable speed limits shown on overhead gantries that can drop well below the standard 70 mph national limit during busy periods or incidents. Your actual average speed on these stretches can be noticeably lower than the speed limit you plan around, so build in extra time on routes that include known smart motorway sections.