IRONMAN 70.3 closes roads across Weymouth and Dorchester on Sunday 20 September, and the council will not sign diversions. Beaminster lights to 2 November.

Dorset is a large rural county with two trunk roads and very few alternatives to them. When the A35 or the A37 shuts, the diversion is not a parallel dual carriageway. It is a lane through a village. That is why a road closure here matters more than the same closure would in a town.

This page tracks the Dorset roadworks that are genuinely booked and dated. Everything below was checked on 18 September 2026 against Dorset Council’s live programme of road works, its live travel updates and the National Highways seven day closure report, which was last updated at 3.30pm on 17 September and covers 17 to 23 September.

IRONMAN 70.3 closes Weymouth and Dorchester roads on Sunday

The county’s biggest event weekend starts on Saturday. IRONMAN 70.3 Weymouth runs on Sunday 20 September, its tenth year, and Dorset Council confirmed the arrangements on 15 September. Competitors swim 1.2 miles in Weymouth Bay, cycle 56 miles through the Dorchester area and run 13.1 miles. IRONKIDS comes to Weymouth for the first time on Saturday 19 September, with up to 1,000 children aged 3 to 15 running between 500 metres and 1.5 kilometres around the Pavilion.

The line that matters most to drivers is the council’s own, and it is blunt:

There are so many different diversion scenarios, that it would be confusing to recommend alternative routes. Therefore, diversions will not be suggested or signed.

So you will not be waved round the closures. Plan the journey before you set off, or do not make it. The council’s advice to anyone inside a closure is to move the car before the restrictions start or wait until the roads reopen.

The full list of affected highways is in the council’s traffic management notices, published through one.network:

The organiser also publishes the bike and run course leaflets and a live closure map, and says emergency services have unrestricted access throughout.

Weymouth car parks, most of which are already shut

Five car parks are affected and three of them have been closed for days already. These are the council’s dates:

  • Lodmoor coach, multi-use and motorhome areas: 5pm on 13 September to 6pm on 23 September
  • Lodmoor main car park: 7pm on 15 September to 6pm on 21 September
  • Pavilion main car park: 13 September to the afternoon of Tuesday 22 September
  • Pavilion Forecourt: Thursday 17 September to the afternoon of Monday 21 September
  • Beach car park: 4am to 6pm on Sunday 20 September

Every other Weymouth car park, the Swannery included, stays open, and the council points drivers at Mount Pleasant Park and Ride on Mercery Road, DT3 5HJ. One small inconsistency to note: the release calls 13 September “Sunday” in one bullet and “Monday” in another. It was a Sunday.

The tips

  • Weymouth Household Recycling Centre, Preston Beach Road: closed all day on Sunday 20 September. It reopens on Monday 21 September, and Portland’s site is the alternative.
  • Dorchester Household Recycling Centre at Louds Mill: closed 9am to 2pm. It reopens from 2pm to 5pm, and those afternoon slots have to be booked.

Bus passengers should check with the operator: the council says services may be disrupted but has not listed the changes. Care providers and residents who need essential access can call IRONMAN race control on 03330 11 66 00.

Closed right now

The A35 is clear from Saturday. The overnight closure at Miles Cross, west of Bridport, ran on the nights of 17 and 18 September for roundabout construction, and the National Highways seven day report lists no further A35 closure in Dorset up to 23 September. The junction stays in a works layout.

On the A31, the westbound carriageway closes between Ringwood and Ashley Heath tonight, Friday 18 September, 9pm to 6am, for barrier and fence safety repairs. Then on Wednesday 23 September, three A31 eastbound slip roads close from 9pm to 6am between Ashley Heath and Verwood: the Ashley Heath entry, the Verwood entry and the Ringwood exit.

On the council’s own network this week, Waterloo Road at Corfe Mullen is closed 9am to 4pm until 22 September, and micro surfacing crews are on Jennys Lane, Lytchett Matravers until Sunday and West Street, Corfe Castle on 19 and 20 September, both of which work through the weekend.

In Weymouth, the 12-week job at the Abbotsbury Road and Chickerell Road junction continues, with temporary signals on the approaches until late November. Details below.

Beaminster has traffic lights until November

This one is new to the page and it is the longest-running restriction in the county. Dorset Council’s live travel updates log it as severe: temporary traffic lights on the A3066 Tunnel Road, both ways, near Beaminster Tunnel, for emergency repairs and roadworks, until 2 November. The entry was last updated on 10 September.

The A3066 is Beaminster’s road to Bridport and the A35. There is no quick way round the tunnel, so allow for the lights rather than trying to avoid them. Seven weeks of shuttle working on a single carriageway road is the kind of thing that quietly adds ten minutes to every trip.

One caveat, and it is the council’s own. Its live travel updates page currently carries a warning that “due to a technical issue, travel alerts are not updating and information listed could be out of date”. The same page says the public reporting form is unavailable from 14 to 22 September for system work. Treat the incident list as indicative this week and check on the ground.

What is closed and when

Everything in this section is a full closure, except the Beaminster lights. Roads are open outside the hours shown, and the council’s night-time schemes are open at weekends.

Dorset road closures and restrictions, 18 September to 30 November 2026 Timeline of road restrictions in Dorset between 18 September and 30 November 2026. A3066 Tunnel Road, Beaminster, traffic lights, to 2 Nov. Waterloo Road, Corfe Mullen, to 22 Sep. Jennys Lane, Lytchett Matravers, to 20 Sep. IRONMAN 70.3, Weymouth area, Sun 20 Sep. Coburg & Edward Rds, Dorchester, 22 to 23 Sep. Rushall & Knoll Lns, Corfe Mullen, 23 Sep to 2 Oct. Weymouth Esplanade, nights, 28 Sep to 17 Oct. B3157 Abbotsbury village, all day, 28 Sep to 9 Oct. Fairfield Road, Dorchester, 28 Sep to late Nov. Wessex Roundabout, Weymouth, nights, 19 to 23 Oct. Abbotsbury & Chickerell Rds, nights, 9 to 16 Nov. Dorset road closures and restrictions, 18 September to 30 November Dark bars close overnight and reopen by morning. Mid bars close in daytime hours. The pale bar is a restriction, not a closure: the road stays open. Overnight closure Daytime closure Event closures Traffic lights, road open 1 Oct 1 Nov A3066 Tunnel Road, Beaminster traffic lights, to 2 Nov Waterloo Road, Corfe Mullen to 22 Sep Jennys Lane, Lytchett Matravers to 20 Sep IRONMAN 70.3, Weymouth area Sun 20 Sep Coburg & Edward Rds, Dorchester 22 to 23 Sep Rushall & Knoll Lns, Corfe Mullen 23 Sep to 2 Oct Weymouth Esplanade nights, 28 Sep to 17 Oct B3157 Abbotsbury village all day, 28 Sep to 9 Oct Fairfield Road, Dorchester 28 Sep to late Nov Wessex Roundabout, Weymouth nights, 19 to 23 Oct Abbotsbury & Chickerell Rds nights, 9 to 16 Nov Weymouth Esplanade is still the longest closure at twenty nights, and it runs into October half term. Sources: Dorset Council live programme of road works, live travel updates and statutory notices, checked 18 September 2026. Chart by The Dorset Post.
Chart by The Dorset Post from Dorset Council's live programme of road works, its live travel updates and its statutory notices.

The one to plan around is Weymouth Esplanade, closed overnight from 8pm to 6am between 28 September and 17 October, followed immediately by the Wessex Roundabout from 19 to 23 October. Twenty nights of seafront closure and then the main roundabout into the town, back to back, ending in half term week. The council’s statutory notice for the job, dated 3 September, sets out the exact extent: Greenhill from Westerhall Road to Waterloo Place, the whole of Waterloo Place, the Esplanade from Waterloo Place to Alexandra Gardens, and the whole of King Street. The same order imposes overnight clearways, and a car left on the closed sections can be removed.

September’s remaining daytime closures run at Corfe Mullen, all 9am to 4pm:

  • Waterloo Road, Corfe Mullen: until 22 September
  • Rushall Lane and Knoll Lane, Corfe Mullen: 23 September to 2 October

Two more closures are in the council’s statutory notices of 10 September, and one of them matters well beyond its village. The B3157 coast road through Abbotsbury is due to close for around 430 metres, from Back Street to Glebe Close, from 28 September until about 9 October, while Wessex Internet installs fibre cable. The signed diversion is the A35, B3159 and A354, which is a long way round, and it removes the coast road as an escape route while the Esplanade is shut at night in Weymouth. The notice is an intention to make the order, published seven days ahead, so check before travelling. The same bundle confirms Fairfield Road in Dorchester closes from 28 September to late November between the car park access and Weymouth Avenue for drainage and place-making works; that order is made. Bindon Lane at Wool also closes in stages from 18 September for resurfacing, as signed on site.

The micro surfacing streets, week by week

The council’s micro surfacing programme is a two-stage job: a removal visit, then a resurfacing visit weeks later. This is the schedule as published on 18 September. Weymouth, Martinstown and Monmouth Avenue are all finished.

Closed 8am to 6pm on the dates shown:

  • Lytchett Matravers: Jennys Lane, 17 to 20 September, running through the weekend
  • Corfe Castle: West Street, 19 and 20 September, a weekend job
  • Dorchester: Coburg Road and Edward Road, 22 and 23 September. Coburg Road is 9am to 2.30pm, Edward Road 9.30am to 2.30pm

The autumn resurfacing batch follows, each road closed 9am to 5pm on its dates:

  • East Lulworth (B3070): 21 September
  • Wimborne: Canonhill Gardens, Livingstone Road and Churchill Road on 22 September, Hardy Crescent 23 to 24, Barnes Crescent on the 24th, Gordon Road on the 28th
  • Sandford: Tyneham Close 28 to 29 September, Keysworth Drive 29 to 30, Sandford Road 30 September to 2 October, Morden Road on 2 October
  • Upton: Chelmsford Road, 2 to 3 October
  • Wareham: Wyatts Lane on 3 October, East Walls 3 to 4 October
  • Stalbridge: Park Grove, 4 to 5 October
  • Portland: Greenways and Shortlands on 5 October, the Greenways spine route 5 to 6, Hamcroft on the 6th, Montrose 6 to 7 October
  • Bradpole and Bridport: Drew Close, Fox Close and Trinity Way 12 to 13 October, Fishweir Fields and Acer Avenue 13 to 14, Victoria Grove 15 to 17 October

Weymouth: 12 weeks of traffic lights, now under way

Dorset Council started work on Monday 7 September at the junction of Abbotsbury Road and Chickerell Road, and expects to be finished by Friday 27 November. Temporary two-way traffic signals are in place on Chickerell Road for the whole of that period. The council’s news release says signals will be on all four approaches to the junction.

The project page also carries a detail the news release leaves out: Abbotsbury Road and Chickerell Road close completely from 9 to 16 November, 8pm to 6am, with a localised signed diversion.

More than 10,000 vehicles a day use Chickerell Road and around 8,000 use Abbotsbury Road, so this is the busiest thing happening on Weymouth’s roads this autumn. The work was scheduled deliberately outside the peak summer holiday period.

The A35, and the handback twelve days away

The A35 is the county’s spine, and for the moment it is not run directly by National Highways at all. The A30 and A35 west of Dorchester are a DBFO concession operated by Connect, with Balfour Beatty doing the work, and that concession hands back to National Highways on 30 September 2026, now twelve days away. The run of closures all summer, Axminster to Bridport, Bridport to Dorchester, Stinsford to Bere Regis, and finally Long Bredy to Monkey’s Jump, which ended on 12 September, was a renewals programme to get the road to the required standard before that handback. That is set out in the National Highways notification republished by Charmouth Parish Council in July, which also names connecta30@balfourbeatty.com as the contact for questions about the works, and confirms that local access inside a closure is maintained by escort if you speak to the gatemen at either end.

The speed limits have also changed. In January 2026 National Highways began delivering the A35 Charmouth to Yellowham speed reduction scheme, a £1.8 million safety project along a 26-mile stretch. The reason given was blunt: the latest five years of validated collision data on that section recorded 199 collisions, 305 casualties and three deaths. The scheme installs average speed cameras in Winterbourne Abbas, Morcombelake and Chideock, and introduces new limits including 50mph between Coombe Road and Monkey’s Jump Roundabout, 50mph between West Stinsford Roundabout and the Cuckoo Lane overbridge, and 30mph between Hollow Way and Howard Road. National Highways said the work would be finished by the end of March 2026 and the restrictions would then be enforceable by police.

The trains: Sherborne and Gillingham are still on a reduced service

If you are catching a train from north Dorset rather than driving, the West of England line is still running short. South Western Railway has cut the Yeovil Junction to Exeter St Davids service to one train every two hours, and runs one train an hour between London Waterloo and Yeovil Junction, because of speed restrictions imposed after dry weather destabilised the track bed between Salisbury and Exeter. Waterloo to Salisbury is unaffected at every 30 minutes.

SWR’s West of England changes page puts the penalty at about 24 minutes extra towards Exeter and about 27 minutes coming back, with journeys to Yeovil Junction roughly 3 minutes longer out and 13 minutes longer back. There is no confirmed end date; the journey planners are loaded to Friday 9 October.

Two things change this Sunday. The autumn timetable starts on 20 September and runs to 12 December, with trains leaving stations between one and five minutes earlier than in the May timetable, so an old screenshot of your usual departure is now wrong. And Dorset Council’s live travel updates still carry the reduced SWR service as a severe alert, last updated on 17 September.

Gillingham (Dorset) and Sherborne are both on this line. Weymouth, Dorchester South and the Purbeck stations are not affected.

The chain ferry

The Sandbanks to Shell Bay chain ferry is the short way between Poole and the Isle of Purbeck, and the alternative is a long drive round through Wareham. It runs every twenty minutes, six crossings an hour, seven days a week, with a four-minute crossing. First sailing from Sandbanks is 7am and the last is 11pm.

When we checked on 18 September the operator’s website sandbanksferry.co.uk reported the ferry running normally, with no maintenance closures listed. The important change from earlier this year stands: since 1 July 2026 vehicles cannot pay at the barrier. The ferry uses number plate recognition and all vehicle tolls are paid online or through the operator’s app, either as a guest or from a pre-loaded account. Tolls set on 1 April 2026 are £1.18 for a motorbike, £6.26 for a car or van and £12.52 for a goods vehicle or bus. Check the live status before you set off, because the ferry does come out of service for weather, tides and scheduled maintenance, and when it does the diversion adds the best part of an hour.

Weymouth park and ride

Weymouth’s Mount Pleasant Park & Ride, just off the A354 on Mercery Road (DT3 5HJ), is the sensible way into the town, and it is the council’s recommended alternative while the Lodmoor and Pavilion car parks are shut for IRONMAN. Parking is free, provided by Dorset Council, and you pay only for the bus.

First Bus Service 2 runs seven days a week. The summer boost that started on 23 July 2026, up to every 12 minutes Monday to Saturday, ends this weekend: First Bus has confirmed that from Sunday 20 September the service runs every 15 minutes Monday to Saturday and every 20 minutes on Sundays and public holidays. That is IRONMAN day, so the drop happens on the busiest Sunday of the month. A ticket is £6.50 for up to two adults and three children into the town centre.

The routes that always catch people out

  • The A35 through Chideock and Morcombelake. Two villages the trunk road runs straight through, now with average speed cameras. Allow more time than the map suggests, in both directions, all year.
  • The A354 into Weymouth. One road carries the seafront, the port, Portland and the park and ride. On event weekends, and IRONMAN is the second in a month, it is the busiest stretch of tarmac in the county.
  • The A3066 at Beaminster. Temporary lights at the tunnel until 2 November, on a road with no realistic alternative.
  • The A31 at Ferndown and Wimborne. The eastern gateway to Dorset and the route most people from the M27 arrive on. It has overnight closures at Ringwood tonight and slip road closures towards Verwood next Wednesday, and it backs up on Friday afternoons regardless.
  • The B3157 coast road between Weymouth and Bridport. Beautiful, and the standard diversion when the A35 shuts. It is single carriageway, hilly and slow, so a closure that adds “twenty minutes” on paper usually adds more. And from 28 September it is due to be cut at Abbotsbury for fibre works (see above), so it stops being a through route at all for up to a fortnight.
  • Corfe Castle on fine weekends. The Purbeck road through the village is narrow and the castle car park fills early, and West Street is being resurfaced on 19 and 20 September. The Swanage Railway between Norden and Swanage exists partly to take cars off it.

Frequently asked questions

What roads close for IRONMAN Weymouth on 20 September?

Roads close along the cycling and running routes across Weymouth and the Dorchester area, and Dorset Council has confirmed it will not suggest or sign any diversions. The full list of affected highways is in the council’s traffic management notices for Saturday’s IRONKIDS and Sunday’s IRONMAN. Weymouth’s recycling centre is closed all day and Dorchester’s from 9am to 2pm, and five Weymouth car parks are affected, three of them already shut.

Is the A35 closed in Dorset this week?

Not after tonight. The A35 at Miles Cross, west of Bridport, closed 8pm to 6am on the nights of Thursday 17 and Friday 18 September for roundabout construction, and National Highways’ seven day report lists no further A35 closure in Dorset to 23 September. The overnight closures between Long Bredy and Monkey’s Jump ended on 12 September.

Why are there traffic lights at Beaminster?

Dorset Council’s live travel updates list temporary traffic lights on the A3066 Tunnel Road both ways near Beaminster Tunnel, for emergency repairs and roadworks, until 2 November. The alert is graded severe and was last updated on 10 September.

Where can I check Dorset roadworks?

Dorset Council publishes a roadworks map and a live programme of resurfacing closures with dates. For the A35, A31 and other trunk roads, which the council does not manage, use the National Highways seven day closure report, which is a downloadable spreadsheet listing every closure by day. Dorset Highways’ traffic team can be reached on 01305 221020.

Are the trains to London affected?

From Gillingham (Dorset) and Sherborne, yes. South Western Railway is running a reduced West of England service because of speed restrictions, with one train an hour to Yeovil Junction and one every two hours onward to Exeter. The autumn timetable also starts on 20 September, moving departures one to five minutes earlier. Weymouth and Dorchester South are not affected.

Are there speed cameras on the A35 in Dorset?

Yes. National Highways’ Charmouth to Yellowham scheme installs average speed cameras in Winterbourne Abbas, Morcombelake and Chideock, alongside new 30, 40 and 50mph limits along the 26-mile stretch.

How much is the Sandbanks ferry in 2026?

£6.26 for a car or van, £1.18 for a motorbike and £12.52 for a goods vehicle or bus, as set on 1 April 2026. Since 1 July 2026 vehicle tolls must be paid online or by app rather than at the barrier. The operator reported the ferry running normally on 18 September.

Is Weymouth park and ride free?

The parking is free. The bus is £6.50 for up to two adults and three children into the town centre on First Bus Service 2 from Mount Pleasant. From Sunday 20 September it runs every 15 minutes Monday to Saturday.

When is Weymouth Esplanade closed?

Overnight, 8pm to 6am, from 28 September to 17 October 2026 for resurfacing, followed by the Wessex Roundabout from 19 to 23 October, according to Dorset Council’s live programme.

Sources

Next: Dorset train times to London if you would rather not drive at all, and things to do in Dorset for where all this traffic is heading.

Dates and prices were correct when checked on 18 September 2026. Roadworks move. Always confirm with the council or National Highways before travelling.