With respect to a connection road linked with a rotary included in a guidance route, a vehicular navigation system acquires a dummy link that is defined to extend towards an inside of the rotary based on road map data. An advancing direction at the rotary is computed by using an angle defined by two dummy links with respect to both an entering road being the connection road on which the vehicle is to approach the rotary and an exiting road being the connection road on which the vehicle is to recede from the rotary. Guidance information at the rotary is outputted based on the computed advancing direction when the vehicle approaches the rotary.