Systems and methods for detecting electromagnetic emissions to monitor and manage road traffic. In one implementation, a system is provided for determining at least one of location, speed, and direction of vehicles on a roadway. The system comprising at least one receiver configured for placement at one or more fixed locations along the roadway to detect a plurality of non-reflected electromagnetic emissions originating from a plurality of vehicles. The system further comprise at least one processor configured to receive signal information from the at least one receiver and to identify in the plurality of non-reflected electromagnetic emissions an electromagnetic waveform of a vehicle. The at least one processor may calculate at least one of a Doppler effect, a phase difference, or a time difference of non-reflected electromagnetic emissions associated with the identified electromagnetic waveform, and determine at least one of a location, speed, and direction of the vehicle.