A control system comprising a mobile electronic device, and a roadside unit, the mobile electronic device comprising: a state detector (6, 24) configured to obtain first information and obtain signal information via short-range wireless communication with a roadside unit; a walking detector (15, 17, 18) configured to obtain second information; and a controller, wherein the controller is configured to specify a position of a user based on the first information, and in response to determining that the user is located in a region through which the user is prohibited from passing based on the position of the user and the signal information, detect whether or not the user walks based on the second information, and execute setting processing for transmitting a caution to the user, if it is determined that the user is located in the region through which the user is prohibited from passing based on the position of the user and the signal information, and also detected that the user walks based on the second information, and not execute the setting processing if it is determined that the user is located in the region through which the user is prohibited from passing based on the position of the user and the signal information, and not detected that the user walks based on the second information, characterised in that the controlle of the mobile electronic device is further configured to output information to the roadside unit to control a display of a traffic ligh (106,108) by the roadside unit, thereby switching a state of a crosswalk on which the user of the mobile electronic device is located to a passable state so that a vehicle cannot pass across the crosswalk, when the user enters an immovable state for some reason during moving in the region through which the user is prohibited from passing. a state detector (6, 24) configured to obtain first information and obtain signal information via short-range wireless communication with a roadside unit; a walking detector (15, 17, 18) configured to obtain second information; and a controller, wherein the controller is configured to specify a position of a user based on the first information, and in response to determining that the user is located in a region through which the user is prohibited from passing based on the position of the user and the signal information, detect whether or not the user walks based on the second information, and execute setting processing for transmitting a caution to the user, if it is determined that the user is located in the region through which the user is prohibited from passing based on the position of the user and the signal information, and also detected that the user walks based on the second information, and not execute the setting processing if it is determined that the user is located in the region through which the user is prohibited from passing based on the position of the user and the signal information, and not detected that the user walks based on the second information, characterised in that the controlle of the mobile electronic device is further configured to output information to the roadside unit to control a display of a traffic ligh (106,108) by the roadside unit, thereby switching a state of a crosswalk on which the user of the mobile electronic device is located to a passable state so that a vehicle cannot pass across the crosswalk, when the user enters an immovable state for some reason during moving in the region through which the user is prohibited from passing.