Welwyn Garden City Roadworks This Week: A1(M) J4 and B651

Almost every journey out of Welwyn Garden City or Hatfield ends up on the same road or the same railway. When the A1(M) shuts between junctions 2 and 4, or the East Coast Main Line closes through the borough, the traffic comes straight through both town centres. This page covers what is closed now and in the next fortnight, which junction does what, and what every council car park charges.

Checked on Monday 5 October 2026.

The A1(M) at junction 4: slip roads shut overnight this week

Junction 4 is the Stanborough interchange, the one most people use for Welwyn Garden City, and National Highways has booked night closures on its slip roads every night from Monday to Thursday. Its seven-day closure report, the file covering Friday 2 to Thursday 8 October 2026, lists:

• Southbound exit slip, junction 4: closed Monday 5, Tuesday 6 and Wednesday 7 October, 22:00 to 05:30, for safety fence repairs, and again on Thursday 8 October, 22:00 to 05:30, for carriageway repairs between junctions 6 and 4.
• Northbound entry slip, junction 4: closed Thursday 8 October, 22:00 to 05:30, for carriageway repairs.

For both, the report gives only “diversion via National Highways network” and does not publish the route. The neighbouring exits are junction 3 for Hatfield and junction 6 for Welwyn village and the north of the town.

Nothing is listed in the Hatfield Tunnel, between junctions 3 and 4, in this file.

The M25 near the borough

• M25 anti-clockwise, junctions 25 to 23 (Enfield to South Mimms): the carriageway is closed Monday 5, Tuesday 6 and Wednesday 7 October, 22:00 to 05:00, for testing works, with the junction 25 and junction 24 entry slips also shut.
• M25 clockwise, junction 22 entry slip (London Colney): closed Monday 5 October, 22:00 to 05:30, for urgent carriageway repairs.
• M25 clockwise, junctions 22 to 23: carriageway and slip road closed Thursday 8 October, 22:00 to 05:30, for maintenance.
• A414 eastbound, Breakspear to Park Street roundabout, near St Albans: closed overnight Monday 5 to Thursday 8 October, 20:00 to 06:00, for the Park Street bypass works. National Highways’ traffic order allows weekend and overnight closures on that stretch to an expected August 2027.

From Monday 12 October, National Highways intends to put a 24-hour 50mph limit on the M25 anti-clockwise between junctions 25 and 24, near Cattlegate Road, for about a week of embankment, barrier and drainage works (ref NH/SE/2026/M25/69).

The report is re-issued as the week goes on and adds nights it did not list before. The live source is the National Highways road closure report. What could not be confirmed today: the file published on the report page this morning still started on Friday 2 October, so anything booked for Friday 9 October onwards is not in it yet.

Trains: buses replace night trains via Welwyn Garden City, 7 and 8 October

Great Northern’s planned engineering work listing, checked for every date from 5 to 19 October:

Wednesday 7 and Thursday 8 October, overnight

From about 23:45 until about 05:10 on both nights, buses replace trains between Alexandra Palace and Stevenage via Welwyn Garden City. Trains between London and Cambridge, Kings Lynn or Peterborough divert non-stop via Hertford North, with longer journey times. Tuesday 6 October has no planned work listed.

Saturday 10 and Sunday 11 October

• At the end of Saturday service (about 01:15 on Sunday), buses replace trains between Welwyn Garden City or Hertford North and Letchworth Garden City.
• On Sunday, buses replace trains between Welwyn Garden City and Hitchin until 08:15, so Welwyn North has no trains before then.
• Until about 08:00, only a reduced service runs between London Kings Cross and Finsbury Park. Paper tickets are accepted on the Underground and London Buses between the two.
• Early on Sunday, northbound trains do not call at Harringay or Hornsey. The listing gives 08:30 in its heading and about 08:05 in its detail.

Monday 12 to Friday 16 October, late nights

Between 23:30 and 05:10 each night from Monday to Friday morning, trains do not call at Hornsey or Harringay, and after 23:50 on the Friday southbound trains do not call there either. Paper tickets are accepted on London Buses. Services through Welwyn Garden City and Hatfield are otherwise unaffected.

Weekend of 17 and 18 October

• Before 05:10 on Saturday 17 October, no trains call at Harringay or Hornsey.
• From about 01:20 until 08:25 on Sunday 18 October, buses replace trains between Stevenage and Letchworth Garden City, Royston and Peterborough, and some late trains from London terminate at Stevenage.
• On Sunday 18 October no trains run between Finsbury Park and Moorgate, which affects the Moorgate trains from Welwyn Garden City. Paper tickets are accepted on the Underground and London Buses.

Next: Monday 19 to Friday 23 October

Between 23:59 and 05:10 each night from Monday evening to Friday morning, buses replace trains between Alexandra Palace and Stevenage via Welwyn Garden City, and Cambridge, Peterborough and Kings Lynn trains divert non-stop via Hertford North.

Great Northern names each bus route by its two ends only. It does not publish the calling points, so check the stop at your station or use the journey planner. Items are added and removed up to the day, so check the planned engineering work page before you travel.

County roads: the B651 at Whitwell, and Lemsford from 12 October

Hertfordshire County Council advertises temporary closures as statutory notices in local newspapers. Each order takes effect only on the days shown by signs at the road.

In force now. This order has been made:

• B651, Whitwell and Kimpton, from 28 September, for water connection works scheduled to take six months. About 2,630m of Horn Hill and Hitchin Road is closed, plus Strathmore Road. The signed diversion uses the A1000 Welwyn Bypass Road, the B197 Digswell Hill and Great North Road, and the B653 Brocket Road and Marford Road, so expect more traffic through Welwyn, Digswell and Lemsford. Whitwell is about six miles north west of Welwyn Garden City.

The short closures listed here last week (Tolmers Avenue in Cuffley, Pottersheath Road and Robins Nest Hill) were each scheduled for one to seven days from late September and have been removed.

From 12 October. The Welwyn Hatfield Times batch dated 23 September carries orders the county council “intends to make”:

• B653 Brocket Road, Lemsford, from Lemsford Village to the Stanborough Road and Great North Road roundabout, about 1,233m.
• B197 Digswell Hill and Welwyn Bypass Road, from Ayot Green Lane to the A1000 and Maran Avenue roundabout, about 331m.
• Cromer Hyde Lane, its whole length, with no alternative route.
• Green Lane, Codicote.

All four sit in one order, closed except for access, for works scheduled to take five days. The Brocket Road diversion is long: it runs through Wheathampstead, St Albans and back along the A1001 Comet Way and the A6129 Stanborough Road. The same batch closes about 2,040m of the B156 Northaw Road West, Northaw, between Vineyards Road and Cattlegate Road, from 12 October for 14 days, with a diversion via Cuffley and the A1000, and 100m of Harmer Green Lane, Welwyn, for five days.

Also from 12 October, about 100m of the B651 Whitwell Road at St Pauls Walden is closed except for access for one day, to replace a telegraph pole. Its signed diversion runs through Wheathampstead, Lemsford, the A1(M) and the A1000 Welwyn Bypass.

From 15 to 19 October. The Welwyn Hatfield Times batch dated 30 September adds:

• Ascots Lane, Welwyn Garden City: a 50mph limit from the A1000 Chequers to Hollybush Lane, about 550m, from 16 October, to accommodate a site entrance. It is scheduled to run for 18 months, when signs are in place.
• Rabley Heath Road and Pottersheath Road, Welwyn, closed except for access from 19 October for five days. The Rabley Heath diversion uses the B656 and B197 Great North Road.
• B656 Hitchin Road, Codicote, about 927m from Whitwell Road to Drivers End, from 19 October for two days. Both published diversions run through Stevenage.
• Porters End Lane, Wheathampstead and Kimpton, from 15 October for one day.

All of these are orders the county council “intends to make”, so the dates can move.

Proposals you can comment on

• Clearways on the A1001 and A414 at Hatfield. The county council proposes no-stopping-at-any-time clearways on parts of the A1001 at Hatfield and the A414 between St Albans, London Colney and Hatfield, among ten roads countywide. Plans are at hertfordshire.gov.uk/trafficorders under ref J00226. The Welwyn Hatfield Times notice gives an objection deadline of 21 October; the same notice in the other county papers says 22 October.
• The Commons, Welwyn Garden City. New double yellow lines are proposed on the south east side next to No.67, for road safety. Objections go to tro.team@hertfordshire.gov.uk by 14 October, quoting ref WH00325.
• Hatfield South and East. The borough council proposes new no-waiting lines on parts of Dearswood Avenue and Woods Avenue, and changes to verge and footway parking rules on parts of Furzen Crescent, Shallcross Crescent, Ash Drive, Bishops Rise, Cherry Way and Garden Avenue. Plans are on the council’s parking consultations page, and objections close on Thursday 15 October.

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.

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 A1(M) closed near Welwyn Garden City this week?

Not the main carriageway, but junction 4’s slip roads are. The southbound exit slip is closed from 22:00 to 05:30 on Monday 5 to Thursday 8 October, and the northbound entry slip on Thursday 8 October, 22:00 to 05:30. No Hatfield Tunnel closure is listed in National Highways’ report up to Thursday 8 October.

Are trains running through Welwyn Garden City late this week?

Not late on Wednesday 7 and Thursday 8 October. From about 23:45 to 05:10 both nights, buses replace trains between Alexandra Palace and Stevenage via Welwyn Garden City. The same happens from 23:59 each night from Monday 19 to Friday 23 October.

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, the seven-day file covering Friday 2 to Thursday 8 October 2026, for every trunk road closure, time, extent and scheme description quoted above.
• Great Northern planned engineering work, checked on 5 October 2026 for each date from 5 to 19 October.
• National Highways’ M25 junctions 25 to 24 temporary restrictions notice, ref NH/SE/2026/M25/69, on the Public Notice Portal, for the 50mph limit from 12 October.
• Hertfordshire County Council statutory traffic notices on the Public Notice Portal: the Welwyn Hatfield Times batches dated 23 and 30 September 2026, the Stevenage Comet batch of 24 September 2026 (Whitwell, Kimpton and St Pauls Walden) and the Herts Advertiser, Comet and Hertfordshire Mercury batches of 1 October 2026 (clearway proposal J00226), for extents, dates, durations and alternative routes.
• Welwyn Hatfield Borough Council’s Hatfield South and East parking notice, dated 23 September 2026, in the Welwyn Hatfield Times on the Public Notice Portal.
• 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.