Drive assist device and method

It is an object of the present invention to provide a drive assist device and method capable of preventing the confusion of a driver at a traffic signal with an arrow lamp. A drive assist device 1 includes an infrastructure information receiver 2 which receives the infrastructure information from an infrastructure apparatus installed on the road, a navigation 3 which acquires various kinds of information including the information regarding a road on which a vehicle travels, a vehicle state monitoring sensor 4 which monitors a state of the vehicle, and an ECU 6. The ECU 6 has a section for determining whether or not it is possible to pass a signal 7, which determines whether or not a vehicle can pass a signal, and a signal waiting time notification control section 8, which determines a signal waiting time of the vehicle and displays it on a display unit 5 when the section for determining whether or not it is possible to pass a signal 7 determines that the vehicle cannot pass a signal. The section for determining whether or not it is possible to pass a signal 7 determines not only a lighting time of only a red signal but also a lighting time of a red signal and an arrow lamp and a lighting time of a yellow signal subsequent thereto are determined as a no-pass time.