A work vehicle control system comprising: a control center configured to transmit/receive predetermined information including a travel permission request signal and a travel permission signal to/from a plurality of work vehicles and control travel of the work vehicles; a work vehicle including an on-board wireless controller (4d, 4e), the on-board wireless controller (4d, 4e) being configured to transmit and receive the predetermined information; a GPS device configured to detect a travel position of the work vehicle, an on-board communication controller, coupled to the on-board wireless controller (4d, 4e) and the GPS device respectively, and configured to, while the work vehicle travels in a predetermined first block section of a travel path on which the work vehicle is to travel, transmit a travel permission request signal to the control center for requesting a travel permission signal from the control center that permits travel in a second block section of the travel path located next to the first block section via the on-board wireless controller (4d, 4e), the on-board communication controller being configured to, when the travel position indicates that the work vehicle is traveling in the first block section, change an interval of transmission of the travel permission request signal in accordance with a distance from a predetermined position in the first block section, located ahead of the work vehicle, the work vehicle includes a brake configured to brake travel of the work vehicle, and the on-board communication controller is further configured to determine an emergency stop point (E1, E2,..., En) in each block section (S1, S2,..., Sn) so that the brake is capable of braking the work vehicle to a stop between the emergency stop point (E1, E2,..., En) and a termination point of the block section and to change the interval of transmission of the travel permission request signal so as to reduce the transmission interval in proportion to a decrease of remaining distance from the emergency stop point. a control center configured to transmit/receive predetermined information including a travel permission request signal and a travel permission signal to/from a plurality of work vehicles and control travel of the work vehicles; a work vehicle including an on-board wireless controller (4d, 4e), the on-board wireless controller (4d, 4e) being configured to transmit and receive the predetermined information; a GPS device configured to detect a travel position of the work vehicle, an on-board communication controller, coupled to the on-board wireless controller (4d, 4e) and the GPS device respectively, and configured to, while the work vehicle travels in a predetermined first block section of a travel path on which the work vehicle is to travel, transmit a travel permission request signal to the control center for requesting a travel permission signal from the control center that permits travel in a second block section of the travel path located next to the first block section via the on-board wireless controller (4d, 4e), the on-board communication controller being configured to, when the travel position indicates that the work vehicle is traveling in the first block section, change an interval of transmission of the travel permission request signal in accordance with a distance from a predetermined position in the first block section, located ahead of the work vehicle, the work vehicle includes a brake configured to brake travel of the work vehicle, and the on-board communication controller is further configured to determine an emergency stop point (E1, E2,..., En) in each block section (S1, S2,..., Sn) so that the brake is capable of braking the work vehicle to a stop between the emergency stop point (E1, E2,..., En) and a termination point of the block section and to change the interval of transmission of the travel permission request signal so as to reduce the transmission interval in proportion to a decrease of remaining distance from the emergency stop point.