The song features music made using synthesisers and electronic percussion only, and the vocal in the verses is delivered in a cold robotic style by Foxx, with an anthemic single word chorus.

Foxx repurposed and re-styled the song during his live shows with Louis Gordon in 1997 giving it the new title of "Overpass".

[9] As of May 2013[update] there were no plans to make the two mixes of "Underpass" featured on this release available elsewhere, except on the CD which was included as part of the VIP Packages for John Foxx and the Maths live shows in April, May and June 2013.

It featured Foxx dressed in suit, tie and overcoat roaming a post-apocalyptic basement with neon light tubes, two keyboard players and two abandoned young children while a black and white film is being projected onto a suspended screen.

The film of Foxx roaming the basement miming the lyrics to the song is interspersed with a mysterious telephone receiver dangling in a park and footage of underpasses, overpasses and urban highways.

A revised version was also made by Karborn for the same DVD to accompany "Mark Reeder’s Sinister Subway Mix".

This digitally restored version also contains footage from the promo video for the successive John Foxx single "No-One Driving" (1980).

A live version of "Underpass" performed by John Foxx and the Maths is included on the Analogue Circuit DVD (2013) and shows specially prepared video footage and imagery by Jonathan Barnbrook.