The　aim　of　this　paper　is　to　present　a　new　software　tool,　the　Imperial　College　Navigation　Software　(ICNavS),　which　enables　the　user　to　run　a　reliable　route　guidance　algorithm　on　real　road　networks.　A　summary　of　the　background　of　the　program　is　given,　followed　by　a　procedure　developed　in　order　to　model　the　features　of　real　road　networks,　as　well　as　missing　data.　Finally,　the　software　is　used　to　run　simulation　experiments　on　a　part　of　West　London＇s　road　network　and　the　results　are　presented.