Abstract: This data display system includes a wireless transmitter mounted on a vehicle. The wireless transmitter is used for transmitting a signal representative of data related to operation of the vehicle. A wireless receiver is mounted on a helmet worn by a driver of the vehicle. The receiver receives a transmitted data signal from the transmitter and generates an output signal. A power supply is mounted on the helmet, and comprises a solar cell and a secondary battery for supplying electric power to the receiver. Converter circuits are connected to an output stage of the wireless receiver for converting the output signal of the receiver into a light display signal of visible rays. A display and mirror are mounted on the helmet for projecting and displaying the display signal from the converter circuits in a forward visual field of the driver.