M3 Junction 3 (Lightwater & Bagshot)
Junction 3 serves Lightwater, Bagshot and the A322 towards Bracknell and Guildford. The stretch running north from here towards the M25 is the busiest counted length of the M3 in Surrey.
How busy is the M3 at Junction 3?
The Department for Transport counts both stretches either side of Junction 3. Both are physical counts, not estimates. These are the 2025 figures.
| Stretch | Length | Vehicles per day | Lorries |
|---|---|---|---|
| J3 Lightwater to Kitsmead Lane flyover | 5.5 miles | 123,417 | 8,271 |
| J4 Frimley down to J3 | 4.5 miles | 118,589 | 6,774 |
© M3Traffic.co.uk · Statistics from the Department for Transport
That makes the northbound stretch the 5th busiest of the 24 measured lengths of the M3, and the busiest anywhere in Surrey.
Traffic here is split almost evenly between the two directions — just 2.3% more westbound than eastbound (62,412 against 61,005). On a road where one junction runs 26% heavier one way than the other, that is unusual, and it means congestion here tends to build in both directions at once rather than in a single commuting peak.
Vans are the story on this stretch: 17,926 LGVs a day, well ahead of the 8,271 lorries.
Live traffic news at M3 Junction 3
Incidents and roadworks between Junction 2 and Junction 4 that we are aware of.
M3 northbound lane 1 and 2 closure (53/7 to 49/2)
05:16 (5:16am)17 Oct 2026reported 10 min ago
- Location
- M3 eastbound between J4 and J3
- Direction
- Northbound
- Lanes closed
- Lane closures
- Reason
- Maintenance work
- Schedule
- 20:00 (8pm) Sat 17 Oct 2026 → 06:00 (6am) Sun 18 Oct 2026
Forecast - not confirmed
This is the news for Junction 3 only, not the whole M3. For the rest of the motorway see all the latest M3 traffic news, the overhead signs and the speed limits in force now.
Updated 05:27 (5:27am) Sat 17 Oct 2026