The world's longest guided busway was born from a railway's ghost

Society · Published 20 October 2026 · Updated 22 October 2026 Swipe more like this →

In short: Imagine a bus that doesn't need a driver to hold the steering wheel. The Cambridgeshire Guided Busway achieves this by using a guidewheel-on-concrete-kerb system. Built atop abandoned railway lines, it serves as a high-speed transit spine, balancing modern engineering with the constraints of historic infrastructure.

The busway connects Cambridge, Huntingdon, and St Ives, featuring two guided sections totaling 16 miles (25 km). The northern section follows the former Cambridge and Huntingdon railway, while the southern section utilizes part of the former Varsity Line to Oxford. This southern stretch, which last saw scheduled trains in 1967, is restricted to single-decker buses due to width constraints. To navigate the narrow Trumpington Cutting, the design employs a bi-directional single-track busway to fit the original double-track railway footprint.

Engineering the route required navigating significant spatial limitations. The busway is 6 meters (20 ft) wide, which is narrower than a standard 9.3-meter (31 ft) rural all-purpose road. To accommodate the narrow space of old railway embankments and under-bridges, engineers opted for a guided layout instead of a standard road. The guidewheel-on-concrete-kerb method allows buses to travel at 55 mph (89 km/h), though they must slow to 30 mph (48 km/h) when crossing public highways.

The project's history is marked by controversy and shifting costs. Originally estimated at £116 million, the cost rose to £181 million by December 2010. It faced significant delays and was even labeled a "white elephant" by the local MP during an independent review in 2010. Despite these hurdles, the busway has proven popular; in its first year of operation, it recorded 2,500,000 trips, exceeding the contractor's prediction of 11,500 journeys per day by a massive margin.

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