Actual time of operation of a plurality of motorized vehicles is automatically recorded utilizing an operation logging circuit installed in each of the vehicles. Each operation logging circuit in each vehicle includes a memory button located in a protected enclosure and programmed with a unique vehicle identification code. Each memory button also has an electronic register for accumulating aggregate vehicle operation time. The memory button is electrically connected to the vehicle direct current electrical system for detecting actuation and deactuation of vehicle operation. For example, the connections to the memory button may be from the contacts for enabling the power steering, contacts for engaging the vehicle for forward and reverse movement, or contacts for the key switch for providing electrical power to the vehicle. A voltage regulating system steps down the power from the vehicle to the level of 5 volts which is required for operating integrated circuits. Each vehicle is provided with an extension circuit that leads to an interrogation port on the exterior of the vehicle and which is accessible from outside the body of the vehicle. A touch memory button reader is brought into physical contact with the interrogation port to interrogate each memory button of each vehicle to copy the vehicle identification number, time and date of interrogations, and the contents of an electronic register indicating accumulated hours of operation of each vehicle. The data copied into the touch memory button reader is downloaded into a central computer system for maintaining maintenance records.