A carriage having a paint nozzle and reflective bead nozzle is provided for rolling along a roadside barrier, such as a guard rail or Jersey wall, to apply a reflective paint stripe on the barrier to improve visibility of the barrier at night. The carriage includes a first set of wheels to support the carriage on an upper edge of the barrier, and one or more additional sets of wheels to maintain proper spacing between the nozzles and the barrier surface being painted. The carriage includes handles with controls for actuating the nozzles. The paint and bead nozzles are connected to the paint system and pressurized bead tank on a paint striper, which may move simultaneously with the carriage along the barrier during the painting process.