Abstract: A radio signaling system (10) provides advanced warning of an approaching transportation vehicle to passengers within a plurality of predesignated pickup regions, thereby minimizing or eliminating the necessity of spending significant amounts of time at roadside pickup points awaiting the arrival of the vehicle. Radio signaling system (10) includes transmitting system (11) on the vehicle broadcasting a radio-frequency signal modulated with a plurality of low-frequency modulation signals having a code of unique frequencies and sequence for each predesignated pickup region. Radio signaling system (10) also includes receiving system (12) selectively adjustable to provide an alarm output signal only upon receipt of the unique low-frequency modulation code for the predesignated pickup region to which receiving system (12) is proximate.