Matthew Broad was waiting for a train at Reading station, England, which it seemed would never arrive. 'I was miffed. But then came the familiar excuse - signal failure.' Matthew wanted to find out more about the causes of signal failure so wrote to the BBC to ask us to find out. Last year in the UK there were more than 19,000 delays of 100 minutes or longer caused by signal failure. Here's what causes it and what Network Rail are doing to alleviate the problem.
One commuter asked the BBC to find out what "signal failure" actually means.