The A1(M) closes both ways through the Hatfield Tunnel on Thursday 17 and Sunday 20 September, 10pm to 5.30am. Buses replace early trains on Sunday 20 and 27.
Almost every journey out of Welwyn Garden City or Hatfield ends up on the same road, and when the A1(M) shuts between junctions 2 and 4 the traffic comes straight through both town centres. This page covers what is closed now, which junction does what, and what every council car park charges, with the tariffs that came into force on 7 April 2026.
Checked on Thursday 17 September 2026.
The Hatfield Tunnel closes both ways on Thursday and Sunday nights
The tunnel work carries on from Tuesday and Wednesday this week. Two more nights are booked, both from 22:00 to 05:30 the next morning.
- Thursday 17 September, 22:00 to 05:30 on Friday. A1(M) northbound, junction 3 to junction 4: carriageway and slip road closure. A1(M) southbound, junction 4 to junction 2: carriageway and slip road closure.
- Sunday 20 September, 22:00 to 05:30 on Monday. The same two closures. The Sunday records add lane closures and sign the diversion “via Local Authorities Network”, which means the A1000 and the A414 through Hatfield and Welwyn Garden City.
Nothing is booked at the tunnel on Friday or Saturday night, or on Monday night. National Highways has not published a scheme page or a diversion map for this work, so the signed route on the night is the only one you will get.
Southbound is the closure that costs you most. It runs from the Stanborough interchange all the way to junction 2, so there is no way back on to the motorway at junction 3 either.
Tuesday 22 September: resurfacing south of junction 3
A different job starts on Tuesday 22 September, 22:00 to 05:30. The A1(M) southbound is closed from junction 3 to junction 1 for surfacing works, with the diversion on local roads. The scheme text describes the job as junction 4 to junction 1. The same night, the northbound entry slip at junction 4 is closed for safety fence repairs, so you cannot join the A1(M) northbound at Stanborough.
Everything else on the trunk roads
From the National Highways closure report, last updated at 15:30 on Wednesday 16 September 2026 and covering the nights from Wednesday 16 to Tuesday 22 September.
- A414 near St Albans. Westbound Park Street roundabout to M1 junction 8 is closed on Friday 18 and Monday 21 September, 22:00 to 05:00, for the M1 and A414 reconstruction scheme. On Tuesday 22 September, 20:00 to 06:00, the A414 westbound is closed from Park Street roundabout to Breakspear junction for the developer-funded S278 works by Galldris Group. National Highways’ traffic order books weekend and overnight closures on that stretch to an expected August 2027.
- A1(M) junction 9, Letchworth Gate. The northbound exit slip is closed on Thursday 17 and Friday 18 September, 21:00 to 05:00, for electrical works.
- M1. Northbound junctions 6 to 8 closed Thursday 17 September, 22:00 to 05:00. The junction 10 roundabout south east quadrant and southbound entry slip closed Friday 18 September, 22:00 to 05:00. Northbound junctions 11A to 13 closed Saturday 19 September, 21:00 to 05:00. Both junction 8 entry slips closed Sunday 20 September, 22:00 to 05:00. Northbound junctions 1 to 5 closed Monday 21 and Tuesday 22 September, 22:00 to 05:30, for surfacing.
- M25. Clockwise junctions 20 to 21A closed Thursday 17 September, 22:00 to 05:30, and Friday 18 September, 23:00 to 06:00, for resurfacing. The anti-clockwise junction 20 exit slip is also closed on Friday night. Clockwise junctions 25 to 26 closed Monday 21 and Tuesday 22 September, 22:00 to 05:30.
Sunday night is quiet, except at the tunnel
Counting the closure records for the whole network gives 307 on Thursday night, 293 on Friday, 115 on Saturday, 90 on Sunday, then 324 on Monday and 303 on Tuesday. Sunday is the quietest night of the week, and it is one of the two nights the tunnel shuts.
Closures change daily. The live source is the National Highways road closure report, which carries a “Last updated” stamp at the top.
Trains: two Sunday mornings with buses
Great Northern’s planned engineering work listings, checked date by date on 17 September, show two early Sunday closures on the line through Welwyn Garden City and Hatfield.
- Sunday 20 September, before 06:50. Buses replace trains between Potters Bar and Welwyn Garden City. Separately, no trains run between London Kings Cross and Finsbury Park before about 07:15, and paper tickets are accepted on London Buses and the Underground between the two.
- Sunday 27 September, until about 08:45. Buses replace trains between Finsbury Park and Welwyn Garden City, and also to New Barnet and Gordon Hill.
- Monday 21 to Friday 25 September, late evenings. Trains towards London will not call at Hornsey or Harringay from 23:30 (from 23:50 on Friday). Change at Finsbury Park or Alexandra Palace.
Saturday 19 September had no planned engineering work listed. Great Northern adds and removes items up to the day, so check the planned engineering work page before you travel.
County roads: closures around the borough’s edges
Hertfordshire County Council advertises temporary closures as statutory notices in local newspapers. The orders that took effect on 14 September in Oaklands, Woolmer Green, Cuffley and near Brookmans Park were booked for between one and five days of works. We found no newer Welwyn Hatfield Times batch for the borough after the one published on 26 August.
Two orders in neighbouring areas matter for drivers from here. Both are orders the county council “intends to make”, and each takes effect only on the days shown by signs at the road.
- Robins Nest Hill, Little Berkhamsted, from 25 September. About 1,881m from the B158 Lower Hatfield Road to Church Road is closed except for access, for works scheduled to take 7 days. The signed diversion runs along the B158 through Essendon, including Essendon Hill.
- Whitwell and Kimpton, from 28 September, for water connection works scheduled to take six months. About 2,630m of the B651 Horn Hill and Hitchin Road, plus Strathmore Road, would close. The signed diversion uses the A1000 Welwyn Bypass Road and the B197 Digswell Hill, so expect more traffic through Welwyn and Digswell. Whitwell is about six miles north west of Welwyn Garden City.
What could not be confirmed today: Hertfordshire County Council sends residents to one.network for utility works and short closures on borough streets. That map needs a browser and returns nothing to an automated check, so this page cannot vouch for small works not covered by a published order.
The junctions, and which one you want
Getting the junction wrong on the A1(M) costs you several miles, because there is nowhere to turn round between them.
| Junction | Roads | Use it for |
|---|---|---|
| 2 | A1001 | Welham Green, south Hatfield |
| 3 | A414 | Hatfield town centre, St Albans, the university |
| 4 (Stanborough) | A414, A6129 | Welwyn Garden City, Hertford, Stanborough Park |
| 6 | A1000 | Welwyn village, north Welwyn Garden City |
The Hatfield Tunnel runs between junctions 3 and 4 for about three quarters of a mile. It is the single point of failure on this stretch: when it closes, whether for planned maintenance or an incident, both carriageways of traffic are pushed onto the A1000 and the A414 through Hatfield and Welwyn Garden City.
Junction 5 is not a full junction and is signed as access only, so for practical purposes the borough has three exits: 3 for Hatfield, 4 for Welwyn Garden City and 6 for Welwyn village.
What parking actually costs
Welwyn Hatfield Borough Council runs 34 car parks across the borough. In Welwyn Garden City town centre the first 30 minutes are free with a ticket, then £2.35 up to two hours at Hunters Bridge and £8.25 for anything over four. In Hatfield, The Common multi-storey gives three hours free, so a two-hour shop costs nothing there and £2.35 here. Those tariffs took effect on 7 April 2026.
Council car parks are free on Sundays and bank holidays, with one exception: Kennelwood Lane in Hatfield charges Monday to Sunday, 7am to 5.30pm.
Moors Walk car park in the Haldens ward is being resurfaced in two phases that started on 1 September and are provisionally due to finish by the end of October, with some spaces closed as the work moves round the site. It is free to park there and it stays open throughout.
Every tariff, the 20 car parks that cost nothing, resident permit prices, Blue Badge rules and the two station car parks are on parking in Welwyn Garden City.
Station parking
The two station car parks are run by APCOA, not the council, and they price very differently. Welwyn Garden City on Osborn Way (AL8 6TU) has 401 spaces, 78 of them with EV charging, and charges £6.20 for up to 12 hours or £7.50 for 24. Hatfield on Great North Road (AL9 5AB) has 369 spaces and charges a flat £10.10 a day, plus a 15p convenience fee, with daily rates expiring at 4am. At weekends Hatfield is the cheaper of the two at £3.80.
Full detail, including season ticket prices and the fare comparison between the two stations, is on Welwyn Garden City train times to London.
Parking at Stanborough Park
Stanborough Park is off the A6129 at junction 4 and its car park is cashless: 20 minutes free, £1.50 for an hour, £6 for three hours and £10 all day, with discounts for Blue Badge holders and registered local residents. On a hot Saturday in the school holidays it fills early, and the park is reachable on foot from central Welwyn Garden City along the Lea. What is actually there is covered on things to do in Welwyn Garden City.
Frequently asked questions
Is the Hatfield Tunnel closed this week?
Yes, on two more nights. The A1(M) is closed northbound from junction 3 to junction 4 and southbound from junction 4 to junction 2 from 22:00 to 05:30 on Thursday 17 and Sunday 20 September, for tunnel works, with the diversion on local roads. On Tuesday 22 September the southbound carriageway is closed from junction 3 to junction 1 for resurfacing.
Are trains running from Welwyn Garden City this weekend?
Saturday 19 September has no planned work listed. On Sunday 20 September buses replace trains between Potters Bar and Welwyn Garden City before 06:50, and on Sunday 27 September buses replace trains between Finsbury Park and Welwyn Garden City until about 08:45.
Which A1(M) junction is Welwyn Garden City?
Junction 4, the Stanborough interchange, where the A1(M) meets the A414 and the A6129. Junction 3 is Hatfield and St Albans; junction 6 is Welwyn village and the north of Welwyn Garden City.
Who do I report a pothole or a roadworks problem to?
Roads inside the borough are Hertfordshire County Council’s responsibility and are mapped at one.network. The A1(M) is National Highways. Car parks are the borough council’s.
Sources
- National Highways road closure report, last updated 15:30 on 16 September 2026, for every closure, time, extent and scheme description quoted above for the nights of 16 to 22 September, and for the nightly network-wide closure counts.
- Great Northern planned engineering work, checked for each date from 17 September to 28 September 2026.
- Highways Act 1980 section 278, for what an S278 agreement is on the A414 at Park Street.
- Hertfordshire County Council statutory traffic notices on the Public Notice Portal: the Welwyn Hatfield Times batch of 26 August 2026, the Hertfordshire Mercury batch of 10 September 2026 (Robins Nest Hill, Little Berkhamsted) and the Stevenage Comet batch of 10 September 2026 (Whitwell and Kimpton), for extents, dates, durations and alternative routes.
- Welwyn Hatfield Borough Council car park records for every tariff, capacity, height limit and season ticket price quoted, all valid from 7 April 2026.
- Major improvements coming to Moors Walk Car Park, Welwyn Hatfield Borough Council, 27 August 2026.
- APCOA Welwyn Garden City and APCOA Hatfield for station car park tariffs.
- Better, Stanborough Park Water Sports Centre for Stanborough parking charges.
- one.network Hertfordshire, the county council’s live roadworks map.
Closures and tariffs change. Confirm with National Highways, Hertfordshire County Council or the borough council before you travel. Where the roads are taking new traffic from is on Welwyn Hatfield planning news.
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