M4 Junction 12: Theale (A4)

Map of M4 Junction 12: Theale — M4 Junction 12: Theale. Map data © OpenStreetMap contributors. Map drawing © Corporate Ace Limited.

Junction 12 at Theale links the M4 to the A4 for west Reading, Calcot and Newbury. Theale is right beside it, with its station under a mile south-west. Reading city centre is about four miles east. Reading Services is between Junctions 11 and 12.

People who live in Theale and Calcot, van drivers working the business parks, and anyone heading for west Reading or Newbury use this junction. The map and our records are below.

Check this junction now: live M4 speed flow map · latest M4 traffic news · M4 serious incidents · M4 accidents

M4 Junction 12 Now: Accidents, Incidents and Roadworks

Live traffic news at M4 Junction 12

Incidents and roadworks between Junction 11 and Junction 13 that we are aware of.

M4 eastbound Jct 13 between the slips carriageway closure

PlannedRoadworksEastbound Road closed

Time now: Wednesday, 21 October 2026, 21:29 (9:29pm)

21:28 (9:28pm)21 Oct 2026reported just now

Location: M4 eastbound between J14 and J13
Direction: Eastbound
Lanes closed: Carriageway closed
Reason: Roadworks
Schedule: 21:00 (9pm) Wed 21 Oct 2026 → 06:00 (6am) Thu 22 Oct 2026

Forecast - not confirmed

🚧HA scheduled: 21:00 (9pm) Wed 21 Oct 2026 → 06:00 (6am) Thu 22 Oct 2026 underway until 06:00 (6am) Thu 22 Oct 2026

+ 3 more near Junction 12 - see all the M4 traffic news →

This is the news for Junction 12 only, not the whole M4. For the rest of the motorway see all the latest M4 traffic news, the overhead signs and the speed limits in force now.

Updated 21:29 (9:29pm) Wed 21 Oct 2026

Live Traffic Speeds at M4 Junction 12

The speed strip below shows the M4 around this junction, both directions, from National Highways’ live data, checked every five minutes.

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60 mph +50–5930–4915–29under 15

closedM62connecting motorwayA6A road👈M1our site: tap for its map

services, on the side you can reach them

crashincidentqueueroadworksspeed limitspeed shown on the signsstop-startoverhead sign

reported by drivers, which can’t always be relied onconfirmed by National Highways

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Go to our live M4 traffic speed flow map ›

In an emergency call 999. To report a problem on a motorway, call National Highways on 0300 123 5000 (24 hours).

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 M4 traffic news →Live M4 traffic speed flow map →

M4 J12 in Our Records

Incidents here, last 13 days20 collisions, 2 breakdowns or obstructions

Typical time to clear–too few cleared incidents to say yet

Slowest daytime hour westbound06:00–07:00average 63 mph (typical 58 mph)

Slowest daytime hour eastbound12:00–13:00average 64 mph (typical 52 mph)

We recorded two incidents at J12 in the last 13 days: both breakdowns or obstructions. Westbound, traffic usually keeps close to its typical speed through the day; the slowest hour is 06:00. Eastbound, traffic has been running faster than its typical speed, even in its slowest daytime hour (12:00).

Average speed by hour of day at J12

our average, last 13 daysNational Highways’ typical speed

Westbound

Eastbound

Incidents per week at J12

collisionsbreakdowns and obstructions* part week: we started recording during it

The latest 2 here

Tue 20 Oct, 12:39 (12:39pm) Broken Down Vehicle ✓Reported by National Highways
M4 eastbound between junctions J13 and J12
✓ Cleared after about 103 minutes (1.72 hours)
Fri 9 Oct, 15:26 (3:26pm) Broken Down Vehicle ✓Reported by National Highways
M4 westbound between junctions J11 and J12
✓ Cleared after about 650 minutes (10.83 hours)

Built from our own records of National Highways’ live data for the M4 either side of J12: speeds from 13 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 M4 J12, Theale
Roads at this junction A4
Nearest town Reading, 4.3 miles east
Junction before J11, Three Mile Cross, about 4.4 miles in a straight line
Junction after J13, Chieveley Interchange, about 10.6 miles in a straight line

Around M4 Junction 12: Theale: Towns and Places on the Map

Map of the area within about 5 miles of M4 Junction 12: Theale, showing the towns, villages, roads and places to visit — The area within about 5 miles of M4 Junction 12. Map data © OpenStreetMap contributors. Map drawing © Corporate Ace Limited.

Places on the Map Near M4 Junction 12
Place	What it is	From the junction
Theale	Railway station	Under a mile south-west
Meadway Shopping Centre	Shopping	About 2 miles east
Reading Retail Park	Shopping	About 2.5 miles north-east
Tilehurst	Railway station	About 2.5 miles north-east
Reading West	Railway station	About 3.5 miles east
Select Car Leasing Stadium	Venue	About 3.5 miles east
TeamSport Indoor Karting	Attraction	About 4 miles east
Oldfield Retail Park	Shopping	About 4 miles east