A fine to be paid by Network Rail for missing performance targets will be used to improve Wi-Fi connectivity for rail passengers.
The government has announced that the penalty - which could be up to £70 million - will help meet its coverage targets.
Last year, the Department for Transport (DfT) said it was aiming to provide free Wi-Fi for 70 per cent of all rail passengers by 2019.
Speaking in September 2013, Transport Secretary Patrick McLoughlin claimed there are "few things more frustrating" than trying to access the internet and being thwarted by a bad signal.
"Passengers deserve to have the best mobile technology," he added.
The DfT said its broadband rollout programme will tackle a number of 'not-spots' along rail corridors with intermittent or poor coverage.
This is with a view to delivering a "consistent and reliable" service for passengers on key routes, it noted.