South Gloucestershire road closures: almost two dozen for motorists to avoid over the next fortnight

South Gloucestershire's motorists will have 23 road closures to avoid nearby on the National Highways network this week.

And two of them are expected to cause major delays – with drivers facing holdups of at least 30 minutes. Another five will cause moderate delays of between 10 minutes and half an hour.

The latest expected works list, with notes from National Highways, shows that seven closures already in place are expected to carry on this week:

• A46, from 8am May 26 to 4pm May 30, slight delays (under 10 minutes): A46 Both Directions Cold Ashton Rbt to M4, junction 18 verge works for horticulture.

• M4, from 6am May 20 to 6am June 16, slight delays (under 10 minutes): M4 westbound, junction 22, 50 mph speed restrictions.

• M48, from 9pm April 3 to 6am July 5, slight delays (under 10 minutes): M48 both directions mobile lane closure for drainage works.

• M4, from 5am March 17 to 9pm September 15, slight delays (under 10 minutes): M4 westbound, junction 19 to 20 - narrow lanes including 24/7 closure of offside running lane for SMART motorway improvements.

• M4, from 5am March 11 to 9pm September 15, slight delays (under 10 minutes): M4 eastbound, junction 20 to 19 - narrow lanes including 24/7 closure of offside running lane for SMART motorway improvements.

• M5, from 5am March 25 to 9pm September 15, slight delays (under 10 minutes): M5 northbound, junction 17 to 16 - narrow lanes for SMART motorway improvements.

• M32, from midnight, March 26 to 5am November 19, slight delays (under 10 minutes): M32, junction 1 to M4, junction 19 and M4, junction 19 to 23 used by GWR Railway Replacement Buses for Bristol Parkway to Newport route.

And a further 16 closures will begin over the next two weeks:

• M4, from 6am May 30 to 6am July 7, slight delays (under 10 minutes): M4 eastbound, junction 22, 50 mph speed restrictions.

• M4, from 8pm May 30 to 6am July 10, moderate delays (10-30 minutes): M4 both directions, junction 22 closed between exit and entry slip road for carriageway repairs. Diversion via exit and entry slip roads.

• M4, from 8pm May 30 to 6am June 1, severe delays (more than 30 minutes): M4 eastbound, junction 23 to 22 Prince of Wales Bridge - carriageway closure for South Wales Trunk Road Agent works prior to POW Bridge, diversion for light traffic via M48 Severn Bridge, diversion for high sided vehicles via A40, M50, M5.

• M49, from 9pm May 30 to 6am May 31, slight delays (under 10 minutes): M49 both directions mobile lane closure for barrier works.

• M32, from 10pm May 30 to 6am May 31, moderate delays (10-30 minutes): M32 northbound, junction 1 to M4, junction 19 carriageway closure for horticultural works, diversion via A4174, A38, M5, junction 16 to M4, junction 20.

• A46, from 8pm May 31 to 6am June 3, slight delays (under 10 minutes): A46 Both Directions M4, junction 18 to Cold Ashton multi-way signals for horticulture.

• M4, from 8pm June 1 to 6am June 2, severe delays (more than 30 minutes): M4 eastbound, junction 23 to 22 Prince of Wales Bridge - carriageway closure for South Wales Trunk Road Agent works prior to POW Bridge, diversion for light traffic via M48 Severn Bridge, diversion for high sided vehicles via A40, M50, M5.

• M5, from 8pm June 1 to 6am June 2, slight delays (under 10 minutes): M5 southbound, junction 14 to 15 lane closure for barrier repairs.

• M49, from 10pm June 1 to 6am June 2, slight delays (under 10 minutes): M49 northbound, M5, junction 18a to M4, junction 22 carriageway closure for central reservation, diversion M5 northbound to junction 15, M4 West.

• M49, from 10pm June 2 to 6am June 3, slight delays (under 10 minutes): M49 southbound, M4, junction 22 to M5, junction 18a carriageway closure for central reservation, diversion M4 eastbound to junction 20, southbound, on M5.

• M4, from 8pm June 5 to 6am July 25, slight delays (under 10 minutes): M4 Both Directions, junction 18 to junction 19 lane closures for bridge construction.

• A4, from 9pm June 5 to 6am June 6, moderate delays (10-30 minutes): M5 southbound, junction 17 exit and entry slip closed for road markings renewal. Diversion for exit slip via, junction 18, St. Brendans and M5 north. Diversion for entry slip via, junction 16 and back.

• M48, from 9pm June 7 to 6am June 9, slight delays (under 10 minutes): M48 eastbound, junction 2 to 1 Severn Bridge - lane closure for structure maintenance.

• M5, from 10pm June 8 to 6am June 9, slight delays (under 10 minutes): M5 southbound, junction 15 exit slips to M4 closed for maintenance works. Diversion via southbound to junction 16, to turn and return northbound.

• M4, from 9pm June 12 to 6am June 14, moderate delays (10-30 minutes): M4 eastbound, junction 23 to 22 Prince of Wales Bridge - carriageway closure for bridge maintenance, diversion via M48 Severn bridge.

• M32, from 10pm June 12 to 5am June 14, moderate delays (10-30 minutes): M4 westbound, junction 19 to 20 - carriageway closure for drainage work, diversion following solid triangle, exit M32 at, junction 1, A4174, A38, join M5 northbound, at, junction 16, join M4 westbound.

National Highways is responsible for maintaining motorways and major A-roads, so closures of smaller roads will not be included in their schedule.