RG04 Speed Restriction Level 2/3 (HKL) Signs with 30km, also known as RS1, RG-4 or a R1-1 sign, are used to indicate a temporary speed limit (tsl) in a work site area with traffic management, to give protection to works on the roadway or in the immediate vicinity and should be accompanied with a TG1 Temporary TW Supplementary Sign. It can be used on Level 2/3 roads.