A lightweight diesel or petrol-driven railway passenger vehicle, typically with four wheels.
- ‘The one referred to in the booklet is the all-ultrasonic car converted from a former New Haven RR Mack railbus.’
- ‘The new lightweight ‘railbuses’ are the result of a link-up with British Leyland.’
- ‘The Astoria-Seaside steam run was replaced by a Mack railbus, and then completely dropped by 1921.’
- ‘After ceasing to haul timber and minerals, the track was used briefly to haul tourists in an old automobile converted into a railbus.’