As the M25 celebrates its 25th birthday, Sally Boazman takes a road trip to see how the motorway has changed our economy, environment and living habits.

The 117-mile (188km) orbital road took more than 11 years to build. It cost £1bn, and used more than two million tonnes of concrete and 3.5 million tonnes of asphalt.

The final section was opened by Prime Minister Margaret Thatcher in October 1986 to a huge fanfare.

Sally Boazman charts the M25's history, follows the team that keeps it moving, and meets a couple who even got married on it.

The Road to Nowhere is on BBC One London, South East, South and East on BBC One on Saturday, 29 October at 17:10 BST and nationwide on the iPlayer thereafter.

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