Saturday
The best time to drive the M4 on a Saturday
On a Saturday the M4 is quietest at 06:00, averaging 62 mph, and busiest at 13:00, averaging 59 mph. Measured from National Highways roadside sensors between 1 May 2026 and 15 June 2026, not estimated.
- Measured, not estimated
- 1 May 2026 to 15 June 2026
Every hour of a Saturday
Darker means slower- 00:0059mph4% below normal
- 01:0059mph5% below normal
- 02:0059mph5% below normal
- 03:0059mph4% below normal
- 04:0060mph3% below normal
- 05:0061mphnormal speed
- 06:0062mphnormal speed
- 07:0061mphnormal speed
- 08:0061mphnormal speed
- 09:0060mphnormal speed
- 10:0060mph4% below normal
- 11:0059mph5% below normal
- 12:0059mph6% below normal
- 13:0059mph6% below normal
- 14:0060mph4% below normal
- 15:0060mphnormal speed
- 16:0060mph4% below normal
- 17:0060mph4% below normal
- 18:0060mph3% below normal
- 19:0061mphnormal speed
- 20:0061mphnormal speed
- 21:0061mphnormal speed
- 22:0060mph3% below normal
- 23:0060mphnormal speed
Across the day that is roughly 2 percentage points closer to free-flowing than the M4's average day, so Saturday is one of the easier days to travel on this road. Hours outside 06:00 to 22:00 are shown but greyed: the small hours are the fastest on almost every road in England, which is true and useless for planning. Averaged across 38 sensors on the M4.
Minutes you save on a Saturday
Quietest against busiest hour62 mph49 min
59 mph51 min
2 minsaved on a 50-mile trip
Other trip lengths: 10 miles saves 0 min, 25 miles saves 2 min. Worked out from the average speed along the whole M4 at each hour, so a trip through its worst junction at rush hour loses more than this.
Questions about the M4 on a Saturday
What is the best time to drive the M4 on a Saturday?
On a Saturday the quietest hour on the M4 is 06:00, when traffic averages 62 mph. That is a measured average from National Highways roadside sensors on the road itself, recorded between 1 May 2026 and 15 June 2026, rather than an estimate. Only 06:00 to 22:00 is considered, because the small hours are the fastest on almost every road in England and saying so helps nobody plan a journey. Roadworks, collisions and weather are not in the average, so it describes what this Saturday usually looks like rather than what today will look like.
What time is the M4 busiest on a Saturday?
The busiest hour on the M4 on a Saturday is 13:00, averaging 59 mph, about 6% below the speed the road runs at when it is clear. The comparison is against this road's own free-flowing speed, so "slower" means slower than the M4 normally manages rather than slower than some national figure. Measured from roadside sensors between 1 May 2026 and 15 June 2026. It is an archive of the usual pattern, not a live reading, so check conditions before you set off.