DRIVING ASSIST METHOD AND DRIVING ASSIST DEVICE

When a host vehicle enters a roundabout, a travel route of the host vehicle is communicated by a direction indicator to other vehicles surroundings the host vehicle. A controller computes a travel route over which a host vehicle and executes driving assist control so that the host vehicle travels along the travel route. In this driving assist method, whether or not the host vehicle has arrived at a roundabout is assessed. When the host vehicle is assessed to have arrived at a roundabout, a positional relationship between a host vehicle entrance for the host vehicle and a host vehicle exit for the host vehicle in the roundabout is assessed based on the travel route. When the host vehicle enters the roundabout, control of the direction indicator lights is performed in accordance with the positional relationship that was assessed.