A busy rail station partially closed over the festive period due to major engineering work fully reopened today only for passengers to be hit by long hold-ups.
There were delays of up to 45 minutes at London Bridge station due to a signalling problem.
Starting during the morning rush-hour and lasting until at least 12 noon, the delays affected passengers with the Southern train company.
Trains at King's Cross, London, were cancelled because of overrunning Network Rail engineering works last month.
Southern and Thameslink trains had been unable to call at London Bridge from December 20 to January 4 due to the engineering work.
There also rush-hour problems today for CrossCountry and First Great Western passengers following an overrun of planned engineering work.
This caused buses to replace trains between Weston-super-Mare and Bristol Temple Meads until around 7.30am, with services back to normal at around 8.15am.
There were other problems for rush-hour train travellers, many of whom were returning to work for the first time since the holiday and also facing season ticket fare rises of up 2.5% which took effect from January 2.
A signalling problem at Merstham in Surrey prevented trains towards London from stopping at Redhill, Merstham or Coulsdon South.
This affected passengers travelling on Southern and Thameslink services.
Another signalling problem, near Eaglescliffe in County Durham, meant buses had to replace trains between Middlesbrough and Darlington stations during the morning peak.
A broken-down train at Harrow & Wealdstone in north west London led to delays between London and Milton Keynes Central in Buckinghamshire.
In the West Midlands a broken-down freight train at Bloxwich meant no trains could run between Rugeley Trent Valley and Walsall.
On Merseyside, an electrical supply problems at Meols caused delays to trains between Bidston and West Kirby.
The problems today follow chaotic scenes in London on December 27 when a Network Rail (NR) overrun led to the closure of King's Cross and Paddington stations.
Transport secretary Patrick McLoughlin said the overrun was totally unacceptable, and NR and the Office of Rail Regulation have both launched inquiries.
The NR inquiry report is expected to be completed by the end of this week.
Next week NR chief executive Mark Carne, who has said he is not taking his annual bonus, is due to appear before the House of Commons Transport Committee to explain the December 27 difficulties.