M25 Junction 15: Thorney (M4)
Junction 15 is where the M25 meets the M4, between London and the West Country and South Wales. Thorney, Richings Park and Harmondsworth are beside it, and Uxbridge is about three and a half miles north. West Drayton station is about a mile and a half north-east, and Heathrow's main terminals about two and a half miles south-east.
This is where the M4 and the M25 cross, beside Heathrow, so airport travellers, hauliers and people heading west to Reading or Bristol come through it. Check it before any trip to the airport or the west.
For the M4 itself, west towards Reading and Bristol or east into London, see our sister site M4 Traffic ↗ (opens in a new tab).
Check this junction now: live M25 speed flow map · latest M25 traffic news · M25 serious incidents · M25 accidents
M25 Junction 15 Now: Accidents, Incidents and Roadworks
Live traffic news at M25 Junction 15
Incidents and roadworks between Junction 14 and Junction 16 that we are aware of.
M1 northbound Jct 6 to Jct 8 carriageway closure
21:28 (9:28pm)21 Oct 2026reported 19 min ago
- Location
- link road from M25 J21 clockwise to M1 J6A northbound
- Direction
- Clockwise
- Lanes closed
- Carriageway closed
- Reason
- Roadworks
- Schedule
- 22:00 (10pm) Wed 21 Oct 2026 → 05:00 (5am) Thu 22 Oct 2026
Forecast - not confirmed
+ 3 more near Junction 15 - see all the M25 traffic news →
This is the news for Junction 15 only, not the whole M25. For the rest of the motorway see all the latest M25 traffic news, the overhead signs and the speed limits in force now.
Updated 21:47 (9:47pm) Wed 21 Oct 2026
Live Traffic Speeds at M25 Junction 15
The speed strip below shows the M25 around this junction, both directions, from National Highways’ live data, checked every five minutes.
Untick all three to see just the speeds. We show the important overhead signs and the mandatory speed limits (red ring); see every overhead sign.
Go to our live M25 traffic speed flow map ›
NOTE: The speed flow, overhead sign messages or other information shown on our live traffic speed flow map is updated every few minutes. We cross check the data and aim to provide warnings if there could be a delay or an inaccurate speed reading. There can be occasions, beyond our control, and despite our best efforts where the speed flow could be inaccurate. We cannot therefore guarantee the speed you can expect on any stretch of the motorway is always accurately shown. However we hope you will find our live traffic speed flow map a useful tool in trying to plan your journey. Safe driving.
All the latest M25 traffic news →Live M25 traffic speed flow map →
M25 J15 in Our Records
Most incidents we recorded at J15 were breakdowns or obstructions; 1 of 4 were collisions. Clockwise, traffic usually keeps close to its typical speed through the day; the slowest hour is 16:00. Anticlockwise, the slowest daytime hour is 07:00, about 8 mph below the typical speed.
Average speed by hour of day at J15
Clockwise
Anticlockwise
Incidents per week at J15
The latest 4 here
- Mon 19 Oct, 19:35 (7:35pm) Collision ✓Reported by National Highways
M25 anti-clockwise between junctions J16 and J15
✓ Cleared after about 14 minutes - Tue 13 Oct, 07:15 (7:15am) Broken Down Vehicle ✓Reported by National Highways
M25 clockwise between junctions J14 and J15
✓ Cleared after about 19 minutes - Sat 10 Oct, 15:17 (3:17pm) Broken Down Vehicle ✓Reported by National Highways
M25 clockwise between junctions J15 and J16
✓ Cleared after about 6 minutes - Sat 10 Oct, 15:15 (3:15pm) Broken Down Vehicle ✓Reported by National Highways
M25 clockwise at junction J15
✓ Cleared after about 19 minutes
Built from our own records of National Highways’ live data for the M25 either side of J15: speeds from 10 days of five-minute readings, incidents from the last 13 days (we started recording incidents on 09/10/2026). Each incident is counted once. Updated every five minutes.
- Junction M25 J15, Thorney
- Roads at this junction M4
- Nearest town Uxbridge, 3.5 miles north
- Junction before J14, Poyle, about 1.6 miles in a straight line
- Junction after J16, Denham, about 4.8 miles in a straight line
Around M25 Junction 15: Thorney: Towns and Places on the Map
| Place | What it is | From the junction |
|---|---|---|
| West Drayton | Railway station | About 1.5 miles north-east |
| Heathrow Terminal 5 | Railway station | About 1.5 miles south |
| Cowley Retail Park | Shopping | About 2 miles north-east |
| Uxbridge F.C. | Venue | About 2 miles north-east |
| Coppins | Historic house or castle | About 2 miles north |
| London Heathrow Airport | Airport | About 2.5 miles south-east |
| Ditton Park Manor | Historic house or castle | About 3 miles west |
| Wraysbury | Railway station | About 3 miles south-west |
