Provided is a navigation system which can contribute to guidance of a moving device such as a vehicle to a destination along a route appropriate from a viewpoint of energy economy. According to second information (VIN, Lj, OPj) on a second probe car Q2, an eco-index ECOj is evaluated for each combination of a link identifier Lj and a vehicle identifier VIN according a first function f1. According to the evaluation result, a second function f2 is set. According to support request information (VIN) on a support subject car Q, an eco-index ECOk is evaluated for an individual link identifier Lk according to the second function f2. The evaluation result or the road traffic information decided according to the evaluation result is recognized by a navigation apparatus (200) mounted on the support subject car Q.