As few as one in five services are expected to run on each of the three days of action - on 21, 23 and 25 June - with the strikes expected to have a knock-on effect on rail travel throughout the week and on traffic levels on the roads.
Network Rail has said that half of all lines will be completely shut on strike days, with disruption around the network on the days in between.
How will the timetables be impacted?
Half of lines around the country will be shut on strike days, with only a fifth of services expected to run, starting no earlier than 6.30am and finishing at 7.30pm.
Services are also expected to be significantly disrupted on the days between strikes. Some operators are running Sunday services on the 22, 24 and 26 while others have cancelled certain trains and warned of potential last-minute changes to timetables.
A focus has been put on intercity and key urban routes around the country.
Services will continue to run between London and Leeds; Newcastle; Birmingham; Manchester; Liverpool; Sheffield; Nottingham; Bristol; Brighton; Norwich and Southampton, but services will start later and finish earlier.
Lines from England to Scotland will remain open but services will be severely cut, with the last London-to-Edinburgh train leaving at 2pm. Services between the two Scottish cities will also continue to operate but there will be no service on any routes north of the two cities.
In Wales, only a handful of lines will remain open, including the main Cardiff-to-Bristol route and parts of the South Wales Valleys lines.
Every rail operator will be affected by the strike even if their staff aren’t part of the action as Network Rail workers who are striking control signalling around the country.
A full emergency timetable is available on the National Rail Enquiries website and individual operators have full details of all their affected services but among the major affected serivces on strike days are:
Avanti West Coast
Services from London Euston will run every hour to Manchester, Liverpool, Birmingham and Preston. No services to North Wales, Shrewsbury, Blackpool and Edinburgh. Trains will not be calling at Stockport, Macclesfield, Stoke-on-Trent or Runcorn.
Two trains per hour from London Fenchurch Street to Shoeburyness via Laindon, and the same frequency from London Fenchurch Street to Pitsea via Rainham. No trains will run via Ockendon or Chafford Hundred.
All departures are cancelled between Monday and Friday.
One train an hour each way will run to Banbury, Aylesbury via High Wycombe and between Aylesbury and Amersham (except Tuesday). On Tuesday, services will be unable to call at stations operated by London Underground. Across the three days no trains will run north of Banbury, to Oxford, or to Aylesbury via Amersham.
A “very limited service” is to run between Bristol Parkway and Plymouth and Birmingham New Street and Newcastle and Edinburgh Waverley. Oone train per hour between Birmingham New Street and Manchester Piccadilly, Leicester, Leeds and York and Reading. No services will run from Birmingham New Street to Bristol Temple Meads, Cardiff Central, Peterborough, Cambridge or Stansted Airport.
East Midlands Railway
One train per hour will run in each direction on most routes. Services will operate between 7.30am and 6.30pm.
Three trains in each direction will be running on strike days.
A maximum of two trains per hour will run between King’s Cross to Ely, Cambridge, Peterborough, Welwyn Garden City and Stevenage via Hertford North.
Great Western Railway
No services in Cornwall and Devon and on South Wales main line, Heart of Wessex line, Severn Beach line, North Cotswolds line and South Cotswolds line. There will be an “extremely limited service” on other routes, which will operate between 7.30am and 6.30pm.
A maximum of two trains per hour on London routes will be running, with no regional or branch line trains.
Trains will only run between Doncaster and London King’s Cross from 7.30am and 6.30pm.
London North Eastern Railway
Around 38% of its usual trains will be running. The last train from London King’s Cross to Edinburgh is at 2pm, while the final service to Leeds will depart at 3.05pm. The last train from Edinburgh to London is at 12.30pm, with the final departure from Leeds at 3.45pm.
London Northwestern Railway
Two trains per hour between London Euston and Northampton, and one per hour between Birmingham New Street and Northampton. No trains will operate between London Euston and Crewe.
There will be no train services and no rail replacement buses on strike days
“Very limited” number of trains on the few running lines, including Leeds to: York; Ilkely; Skipton; Sheffield and Bradford.
Two trains per hour between Edinburgh and Glasgow via Falkirk. No trains will run north of Glasgow or Edinburgh on strike days.
South Western Railway
Four trains per hour between London Waterloo and Woking, and two per hour between London Waterloo and Basingstoke.
Most routes will be closed and a “severely reduced” service will run on Dartford line, high speed St Pancras to Ashford line, and Orpington line.
Two trains running per hour from London Bridge and London Victoria to south-east London and the coast. Services will run on the Brighton Mainline to London Bridge and London Victoria, with additional trains from Tattenham Corner, Epsom Downs, Sutton and West Croydon, via Crystal Palace.
Two trains per hour will run both north and south lines. No trains between London St Pancras and London Bridge.
One train per hour on Manchester to York routes, one train every two hours Preston-Manchester Airport and Sheffield-Cleethorpes. Two trains per day between Edinburgh and Newcastle. Yarm, Scarborough, Seamer, Malton, Selby, Brough and Hull stations will be completely closed.
Transport for Wales
On Tuesday and Thursday a reduced service will run between Radyr and Treherbert, Aberdare and Merthyr Tydfil, with replacement bus services between Radyr and Cardiff Central. There will be a reduced service between Radyr and Treherbert, Aberdare and Pontypridd, with replacement buses in operation between Radyr and Cardiff Central on Saturday.
West Midlands Railway
Most services cancelled. Maximum of two trains per hour on the Lichfield Trent Valley to Bromsgrove line, one per hour on Birmingham New Street to Wolverhampton and Birmingham International.