Single-track

[…]a single-track main line between Richmond, Ind., and Norwood Heights, Ohio

It was once the busiest singletrack section of railway line in the country but, almost three decades after its closure, the short route which once linked Tunbridge Wells’s two stations is a ghostly presence

On the now defunct Guildford-to-Horsham line, there was a foolproof way of avoiding collisions on singletrack lines

Basingstoke-Exeter will test this. From Salisbury westwards, it's largely single-track since British Rail downgraded it in 1967. There's a ten-mile loop between Templecombe and Yeovil, as well as shorter loops at Chard, Axminster and Honiton.

Highglen elementary school will maintain a dual-track system of a Montessori program and a regular neighbourhood school program side-by-side for one more year, Prince George trustees decided this week. In January, the board had voted in favour of making the Montessori program into a single-track program where it would occupy an entire school like Highglen.

This week the district placed Cathedral City Elementary and Landau Elementary back to a “single-track” schedule in which all students attend school on the same days throughout the year. A few years ago, overcrowding forced the district to split students into tracks so that some kids attended classes while others were on vacation.