Commuters and business travellers face chaos and disruption after Easter as rail workers yesterday announced a four-day walkout.
Members of the RMT and TSSA unions are striking over rail safety and job security.
The unions' discussions with National Rail and conciliation body Acas ended in stalemate.
The industrial action, which will starts on April 6, will create major congestion on roads in and around London and the South East of England according to the AA.
Bob Crow, the RMT's general secretary, said negotiators had worked flat-out to try and avoid strike action.
"Network Rail, in a drive to slash 21% from its budget, wants to axe 1,500 maintenance posts, lump maintenance functions onto overworked signalers, rip up agreements and impose changes that will clearly undermine safety across our railways and make another Hatfield, Potters Bar or Grayrigg disaster an inevitability.
The RMT said its signallers would strike from 6am until 10am and 6pm until 10pm from April 6-9.
But 12,000 Network Rail workers and 800 TSSA members working as supervisors will continuously strike from 6am on April 6 until 11.59pm on April 9.
The AA is urging people to change their travel plans around Easter if possible.
It is the first national rail strike in Britain for 16 years.