A mobile unit communication apparatus, including a wireless transceiver, is provided at a mobile unit. At the mobile unit communication apparatus, a surrounding object detection unit detects objects surrounding the mobile unit. The surrounding communication impediment detection unit detects a likelihood of an impediment to communication in the surroundings of the mobile unit from conditions for surrounding objects detected by the surrounding object detection unit. A relay communication unit transmits information received by the wireless transceiver from the wireless transceiver. A relay wait time setting unit sets a time until information received by the wireless transceiver is transmitted by the relay communication unit from the wireless transceiver longer for a larger likelihood of an impediment to communication detected by the surrounding communication impediment detection unit.