1. A route guidance system for a vehicle, comprising: a current-location detecting unit that detects the current location of a vehicle; and a controller that: searches a route to a destination based on the current location; calculates a recommended lane for each road on the searched route; sets a guidance intersection based on the searched route; sets a route guidance point at a predetermined point before the guidance intersection; provides route guidance through the guidance intersection when the vehicle reaches the route guidance point; determines, regardless of on which lane the vehicle is traveling: that lane planning cannot readily be performed by a user at the guidance intersection, when the vehicle makes a right turn at the guidance intersection, if there are a plurality of lanes from which the right turn is available and the recommended lane is not a rightmost lane but a lane other than the rightmost lane among the plurality of lanes from which the right turn is available, or when the vehicle makes a left turn at the guidance intersection, if there are a plurality of lanes from which the left turn is available and the recommended lane is not a leftmost lane but a lane other than the leftmost lane among the plurality of lanes from which the left turn is available, and that the lane planning can readily be performed by the user at the guidance intersection, when the vehicle makes a right turn at the guidance intersection, if there are a plurality of lanes from which the right turn is available and the recommended lane is a rightmost lane among the plurality of lanes from which the right turn is available, or when the vehicle makes a left turn at the guidance intersection, if there are a plurality of lanes from which the left turn is available and the recommended lane is a leftmost lane among the plurality of lanes from which the left turn is available; performs lane guidance at the route guidance point if it is determined that the lane planning cannot readily be performed by the user at the guidance intersection; and does not perform the lane guidance at the route guidance point if it is determined that the lane planning can be readily performed by the user at the guidance intersection.