1. A course determining system of a vehicle for determining a running course as a path along which the vehicle travels, comprising: detecting means for detecting a plurality of objects that are present around the vehicle; determining means for determining whether a passable road on which the vehicle can enter is present between the plurality of the objects when the plurality of objects are detected by the detecting means such that: when it is determined that there is no road on which the vehicle can enter between the plurality of objects, the plurality of objects is determined as a single object; when it is determined that a road on which the vehicle can enter is present between the plurality of objects, the plurality of objects is not determined as a single object; when the vehicle proceeds between the plurality of objects and it is determined that no road which the vehicle can enter is present between the plurality of objects, a driving assisting process is carried out; when the vehicle proceeds between the plurality of objects and the determining means determines that a road on which the vehicle can enter is present between the plurality of objects, the driving assisting process is not carried out; and when it is determined that a road is present between the plurality of the objects, the determining means determines that there is no passable road between the objects when the road is a no-entry road which the vehicle is inhibited from entering; and course determining means for determining the running course based on at least one road including the passable road between the objects such that when it is determined that a road on which the vehicle can enter is present between the plurality of objects, the running course of the vehicle is determined based on roads including the passable road located between the plurality of objects.