Drivers using the A12 southbound through Essex this Wednesday can make the evening journey easier by planning before the working day gets busy. National Highways is resurfacing the A12 and refreshing road markings between Chelmsford and Colchester. The current programme includes a southbound closure from junction 25 at Marks Tey to junction 23 on weeknights between 9pm and 5am, weather permitting.
The southbound phase runs from Monday 10 August to Friday 12 September. If your route uses this part of the A12 tonight, check the latest information before leaving, allow extra time and be ready to follow the signed diversion.
What the Wednesday closure means
The closure is scheduled to begin at 9pm. Journeys earlier in the day may operate normally, but drivers setting off in the evening could meet traffic building near Marks Tey as vehicles leave the A12. The work is weather dependent and plans can change at short notice, so a morning check is useful, but a final check shortly before departure is essential.
If you can choose when to travel, compare an earlier departure with the expected diversion time. If you must travel after 9pm, tell anyone expecting you that the journey may take longer and avoid committing to an unrealistically tight arrival time.
Understand the official southbound diversion
National Highways advises southbound traffic to leave at junction 25 at Marks Tey, follow the A120 towards Great Notley, then take the A131 and continue to junction 19 before rejoining the A12. Temporary signs on the road remain the authority. A navigation app may help with general progress, but it can lag behind temporary traffic management.
- Enter the destination while parked and keep the phone mounted legally.
- Allow enough fuel or battery charge for the longer route and slower traffic.
- Identify one safe stopping point before you leave.
- Follow yellow diversion signs and never stop in a live lane to change navigation.
Prepare the car during the morning
A few checks now are easier than trying to solve a problem beside an unfamiliar road at night. Check tyre condition and pressure, clean the windscreen, confirm every exterior light works and top up screenwash. Make sure the driver has any required glasses, the phone is charged and breakdown-cover details are accessible.
Pack water and essential medication where they can be reached without unloading the boot. Secure loose items so they cannot move during braking. A high-visibility vest and torch should be easy to find. A warning triangle can be useful on suitable roads, but never place one on a motorway. Keep a window breaker and seatbelt cutter fixed within adult reach inside the passenger compartment rather than buried in luggage.
A compact roadside kit for diversions
The JUFO 3-in-1 Roadside Breakdown Kit is £17.95. It combines a high-visibility vest, warning triangle and compact window breaker with seatbelt cutter. Store the vest and triangle securely in the boot, and position the escape tool where an adult can reach it from a seat.
If the journey does not go to plan
If the vehicle develops a fault, move to a safe place away from live traffic if possible, switch on the hazard lights and contact breakdown assistance. On a motorway or high-speed road, leave the vehicle only when it is safe, move behind a safety barrier and stay well away from traffic. If you cannot leave safely, remain belted in the vehicle and call 999 if there is immediate danger.
Do not attempt repairs beside fast traffic and do not walk along the carriageway looking for a diversion sign. Staying visible and away from moving vehicles matters more than recovering a few minutes.
Your A12 morning checklist
- Check the latest A12 closure information now and again before departure.
- Plan around the 9pm start and allow extra journey time.
- Expect the signed route via the A120 and A131.
- Check tyres, lights, windscreen, fuel or charge.
- Secure roadside equipment and keep the phone charged.
- Share your expected arrival time if travelling late.
Good preparation turns a planned closure into a manageable route change. Leave enough time, follow the signs, drive to the conditions and take a break if the diversion makes your journey longer than expected.
Source checked 12 August 2026: National Highways — A12 Chelmsford to Colchester maintenance. Closure timings may change at short notice and are weather dependent.
