There is described a method for reserving a parking space for a vehicle using a web-enabled computing device and its positioning system. The method comprises: requesting, while the mobile computing device is at a present location, an unreserved and/or unoccupied parking space thereby defining a selected parking space; computing an estimated travel time from the present location of the mobile computing device to the selected parking space; based on the estimated travel time, automatically calculating, an initial reservation period for the selected parking space; accepting the initial reservation period; and upon the accepting, generating and transmitting a reservation signal to the parking system database, the reservation signal comprising an ID of, and the initial reservation period for, the selected parking space and instructions for changing the status of the selected parking space from unreserved to reserved.