Overground: The Railway—Keeping Britain on Track

King's Cross is a gateway to Leeds, York, Newcastle and Edinburgh for the 47 million people who travel through here every year. Its 1970s concourse is cramped and dark, and does nothing to help the spirits of the passengers.

Running the trains would be far easier if it wasn't for the public. For driver Jason, driving the trains on the "Real Ale Trail" (a pub crawl by train) is the most dreaded shift of the week as drunken party-goers fill his train.

It's a packed schedule and when a train accidentally cuts through some vital signalling cables, the track staff are under intense pressure from their bosses to get the hundreds of irate passengers on the move again.

The West Coast Mainline is the busiest route in Europe - linking London to Glasgow with Birmingham, Manchester and Liverpool in between. So when engineering upgrade work happens to fall on the FA Cup final weekend, the railway staff find themselves even more unpopular than usual.

With 20,000 miles of track criss-crossing the country, and 7 million neighbours, the railway has to manage its local communities as best it can. This episode joins MerseyRail revenue inspectors trying to clamp down on ticket evasion and drunk passengers from the alcohol-fuelled Orange Parade.

When overhead power lines are ripped down by a freight train, it spells chaos for the country's West Coast Main Line and days of disruption for passengers at Glasgow Central Station ... but even without engineering problems, this is a network under constant strain.