A system and method for the application of friction-modifying coatings to roadways, walkways, pathways and other areas subject to vehicular, human or animal traffic, the system and method comprising the controlled, simultaneous application of binder and filler to a surface of a substrate, using a mobile device which passes over the substrate as the binder and filler are being applied. The system includes a frame coupled to a vehicle. A spray bar is mounted on the frame and includes an array of spray nozzles coupled to a resin container. An air knife is mounted on the frame and coupled to an air compressor for generating an air curtain. An aggregate dispenser bar including at least one aggregate dispenser is coupled to an aggregate bin and mounted on the frame for dispensing aggregate.