Abstract: This paper presents a tool for advanced traveller’s information systems (ATIS) development and testing. The ATIS provide travellers with real time traffic information to help them make informed route choices in minimizing their travel costs. The ATIS also provide traffic managers with a powerful means to implement transport policy and to handle incidents through influencing travellers’ dynamic route choice. We have developed a portable program to implement a variable message sign (VMS) based route guidance system in a simulated urban city environment. Expected travel delay is the primary information distributed by the VMS. Individual drivers’ inherent characteristics (i.e. awareness and aggression), their minimum acceptable travel delay and perceived travel cost determine their dynamic route choice. The Adelaide CBD microscopic traffic model is used to test this program. The preliminary results demonstrate the capability of the program in mimicking traveller’s dynamic response to VMS (and traffic information in general), which makes it an ideal tool for ATIS strategy development. This program also improves the accuracy of microscopic traffic simulation of incidents and their impact on urban traffic networks.