A traffic signal state detection apparatus includes a first traffic signal information obtaining part that obtains first traffic signal information generated by a first infrastructure, a first output process part configured to calculate, based on the first traffic signal information from the first traffic signal information obtaining part, a second traffic signal information obtaining part that obtains second traffic signal information generated by a second infrastructure that is different from the first infrastructure, a second output process part that calculates, based on the second traffic signal information from the second traffic signal information obtaining part, and an output part that outputs one of the first and second remaining times in a situation where the first and second output demands are generated simultaneously, the output remaining time being related to one of the first and second output demands that is being continuously generated before the other is generated.