Navigation system comprising - means for determining a position of a vehicle, - means for predetermining a driving route of said vehicle, - means for determining a driving maneuver in accordance with said predetermined driving route, and - means (104, 105, 110, 111) for outputting indications relating to said determined driving maneuver to a driver of said vehicle, - means for alerting said driver to potential wrong way driving including - means for detecting a potential wrong way driving situation and - means (202, 104, 105, 110, 111) for outputting an indication relating to said potential wrong way driving situation to said driver through the means (104, 105, 110, 111) for outputting indications, comprising means for determining a content of indication output to the driver, which comprises means for determining a driving recommendation for staying on said predetermined driving route by avoiding the detected potential wrong way driving situation, CHARACTERISED in that said means for detecting a potential wrong way driving situation comprises: - a plurality of sensor means (102, 113-120) for detecting at least one value of a plurality of parameters relating to an operating state of said vehicle, - means for determining at least one set value of said parameter(s) relating to an operating state of said vehicle in dependence on said predetermined driving route, wherein the said at least one set value of parameter(s) is only determined within a predetermined distance of a location where potential wrong way driving situation may occur, - means for comparing said detected value(s) of said parameter(s) and said determined set value(s) of said parameter(s), and - means for judging the result of said comparison for detecting a potential wrong way driving situation. - means for determining a position of a vehicle, - means for predetermining a driving route of said vehicle, - means for determining a driving maneuver in accordance with said predetermined driving route, and - means (104, 105, 110, 111) for outputting indications relating to said determined driving maneuver to a driver of said vehicle, - means for alerting said driver to potential wrong way driving including - means for detecting a potential wrong way driving situation and - means (202, 104, 105, 110, 111) for outputting an indication relating to said potential wrong way driving situation to said driver through the means (104, 105, 110, 111) for outputting indications, comprising means for determining a content of indication output to the driver, which comprises means for determining a driving recommendation for staying on said predetermined driving route by avoiding the detected potential wrong way driving situation, - means for detecting a potential wrong way driving situation and - means (202, 104, 105, 110, 111) for outputting an indication relating to said potential wrong way driving situation to said driver through the means (104, 105, 110, 111) for outputting indications, comprising means for determining a content of indication output to the driver, which comprises means for determining a driving recommendation for staying on said predetermined driving route by avoiding the detected potential wrong way driving situation, - a plurality of sensor means (102, 113-120) for detecting at least one value of a plurality of parameters relating to an operating state of said vehicle, - means for determining at least one set value of said parameter(s) relating to an operating state of said vehicle in dependence on said predetermined driving route, - means for comparing said detected value(s) of said parameter(s) and said determined set value(s) of said parameter(s), and - means for judging the result of said comparison for detecting a potential wrong way driving situation.