Network Rail warned over track improvements
4 October 2013 Last updated at 21:06 BST
Network Rail has been told to improve tracks and signalling in the West Midlands or face a big fine.
It has caused 70% of all delays on the West Coast Mainline and 35% of those delays are due to infrastructure faults.
But Network Rail is in the middle of a £40m improvement package for the railway line and it has now brought in a new piece of machinery to replace track more quickly.
BBC Midlands Today transport correspondent Peter Plisner reports.