Friday is when the M4 westbound carries holiday and weekend traffic out of London towards Bath, Bristol, the M5 for Devon and Cornwall, and Wales, on top of the usual commute.

The charts show how the latest Friday moved, westbound and eastbound, against the Friday before and the usual speed, and the cards name the slowest stretch.

The M4 on Other Days

• M4 on Mondays
  Hour by hour, westbound and eastbound
• M4 on Tuesdays
  Hour by hour, westbound and eastbound
• M4 on Wednesdays
  Hour by hour, westbound and eastbound
• M4 on Thursdays
  Hour by hour, westbound and eastbound
• M4 on Saturdays
  Hour by hour, westbound and eastbound
• M4 on Sundays
  Hour by hour, westbound and eastbound

For the road right now, see the live M4 speed flow map and the latest M4 traffic news, or look up any junction on the M4 junctions page.