Live from National Highways

A421 Roadworks

Lane closures, overnight works and planned schemes on the A421, straight from the National Highways feed.

0Running now

0Severe delay

3Starting soon

Home › Traffic › Roads › A421 › Roadworks

Severe Eastbound Starting soon

The A421 eastbound between junctions with the A4280 and A1

🔨 Roadworks

🚦 1 of 2 lanes closed ✅ The event is expected to clear between 05:00 and 05:00 on 25 September 2026

Severe Eastbound Starting soon 🌙 tonight

A421 eastbound Water End Interchange to Black Cat Roundabout carriageway closure

Overall Scheme Details: A1 / A421 both directions Biggleswade to St Neots - carriageway closures, lane closures, narrow lanes, permanent layby closures and

Diversion: diversion routes for construction - bypass/new on behalf of National Highways

✅ until 06:00 Fri 25 Sep

Severe Westbound Starting soon 🌙 Sat 26 Sep

A421 westbound A6 Marsh Leys to M1 Jct 13 carriageway closure

Overall Scheme Details: A421 both directions Marsh Leys to Brogborough - carriageway closure for white lining/road markings on behalf of National Highways

✅ until 07:00 Sun 27 Sep

❓ A421 roadworks — Frequently Asked Questions

Are there roadworks on the A421 right now?

No roadworks are currently running on the A421 according to National Highways.

Is the A421 closed tonight?

3 closures are scheduled on the A421 in the next 72 hours. Each one is listed above with its window and diversion.

When are A421 roadworks usually carried out?

Most National Highways lane closures on the A421 run overnight and are lifted before the morning peak (07:00–09:00). Full carriageway closures are usually weekend nights, with a signed diversion.

🛣️ Data from National Highways · All UK roadworks · Overnight closures · A421 live traffic
Roadworks change at short notice. Always follow signs and signals on the road.

🚗 A421 pages

A421 live traffic →

A421 Trunk Road · 25 miles. Live incidents, junction status and collision history.

🚧 Roadworks elsewhere

🇬🇧 All UK roadworks → 🌙 Tonight's overnight closures → 🚧 M1 roadworks → 🚧 A6 roadworks → 🚧 A428 roadworks →

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