20 years on from rail privatisation, commuter fares are far higher than in many other major European countries, punctuality is in decline, and overcrowded commuter services are reaching bursting point. On the plus-side, sausage rolls are no longer offensive weapons.

On a journey across a rail network under increasing strain, Nick Hewer and Margaret Mountford climb on board Britain's trains to find out whether we're getting value for money.

Where exactly is the £8bn of fares and £4bn of public money that go into our trains each year being spent? How much can train operating companies actually do to improve their services? And who is to blame for the ongoing and endless train delays?