Two trains carrying up to 300 people came within thirteen seconds of crashing into each other just outside Oxford.
The First Great Western services between London Paddington and Oxford came close to disaster in August 2007 after one driver failed to stop at a signal.
A report on the incident discovered that his train continued through Didcot Junction without authorisation, narrowly avoiding another service operating in the opposite direction.
According to investigators, “Had the circumstances been slightly different this event could have resulted in the two trains colliding.”
