Vehicle　navigation　systems　provide　drivers　with　real-time　remaining　signal　time　information　from　a　significant　distance　away　from　intersections,　enabling　them　to　adjust　their　driving　behaviors　proactively.　The　advanced　navigation　function　has　established　a　new　paradigm　for　driving　behavior　and　traffic　flow.　This　study　first　examines　the　alterations　in　driving　behavior　resulting　from　the　signal　countdown　of　vehicle　navigation　systems　(SCVNS)　and　integrates　these　effects　into　the　car-following　model.　Second,　the　study　investigates　the　modifications　in　driving　behavior　induced　by　SCVNS　using　the　full　velocity　difference　(FVD)　model,　focusing　on　its　implications　for　traffic　efficiency,　safety　and　environmental　impact.　Finally,　the　study　quantifies　the　influence　of　key　parameters　in　the　model　on　traffic　flow　and　validates　the　effects　of　SCVNS　across　different　car-following　models.　The　results　indicate　that　SCVNS　enables　vehicles　to　adjust　their　driving　behavior　proactively,　enhancing　traffic　efficiency　at　intersections　and　reducing　the　risk　of　rear-end　collisions,　although　it　may　slightly　increase　emissions.　Additionally,　the　effects　of　SCVNS　are　validated　across　various　car-following　models.