may be somewhat less readable, but is easier to change between routes/destinations and to update for changes to a transit system's route network. However, given the long life of public transit vehicles and of sign rolls, if well made, some transit systems continue to use these devices in the present day.

The roll is attached to metal tubes at the top and bottom, and flanges at the ends of the tubes are inserted into a mechanism which controls the rolling of the sign. The upper and lower rollers are positioned sufficiently far apart to