roller blind
A destination indicator blind on buses and trains having two rollers, top and bottom. It can be rolled to display various destinations and route numbers through a small window.
roller blind: the wound band that shows where the bus is really going
A roller blind is a long fabric strip wound between two cylindrical rollers, mounted above or below a window aperture on a bus or train. It displays destination names, route numbers, and service information as the operator rotates the rollers to advance the blind and present different sections of printed text through the viewing window. The mechanism is purely mechanical, using a hand crank or lever on the driver's side to unspool and respool the material.
The fabric itself, typically linen or cotton canvas, is printed with destination text and numbers at regular intervals along its entire length. Each complete circuit of the rollers represents one full rotation through all available destinations on that route. Older urban buses commonly carried multiple blinds per vehicle: one for the front windscreen showing the main destination and route number, another for the side panel showing stops, and sometimes a third for the rear. The blind is wound tightly around the lower roller, and as the crank turns, it unwinds from the lower roller and winds onto the upper one.
Wear and operator error
Roller blinds wear at predictable points. Repeated winding causes the fabric to thin and fray at the edges where it contacts the roller shafts. The printed ink can also fade under ultraviolet light, making text illegible after several years of street use. Operatorsoccasionally wind the blind past the correct destination or fail to advance it between trips, causing customer confusion. Jammed rollers from dirt buildup or torn fabric can prevent any movement at all, requiring the blind to be removed and rewound at a depot.
The roller blind dominated public transport signage from the 1920s through the 1980s because it required no electricity, was cheap to manufacture, and could be changed quickly without removing hardware. It persisted longest in smaller cities and rural services. The invention of LED and electronic destination displays gradually displaced them from the 1990s onward, though some heritage and heritage-operated vehicles retain them for authenticity or continued utility on short fixed routes where the limited destination options justify the mechanism's simplicity.