Traffic congestion, in Hong Kong, is a serious prohlem and is unlikely to he solved by addinq more road capacity. Due to spatial limitation in the most congested areas and latent demand induced by the added capacity, transport planners and economists have shifted their focus from the supply side to the demand side for tackling traffic congestion, Road pricing can form part of a traffic demand management strategy to provide an efficient, equitahle and flexible solution to handle traffic congestion problems in the long term. The Government of the 'Hong Kong Soecial Administrative Region appointed a consultancy to investigate the requirement for electronic road pricing (ERP) system implementation, the social impacts and its implications, As a Part of the study requirement, A discrete choice model with multinomial logit formulation was develooed in order to assess major behavioural change in traveller responses due to ERP. From a review of the previous Hong Kong ERP study and other worldwide experience. the most likely responses of travellers to ERP are identified as paying the road pricinq charge, changinq the time of travel,changing the route taken, switching to other modes, switching to use Park and Ride facility, increasing vehicle occupancy for ERP cost sharing and suppressing of trip making. A stated preference (SP) survey was designed to collect information upon individuals' likely responses to the'alternative ERP responses defined ahove, The SP survey results were analysed to derive the ERP assessment modeI coefficients, The model was integrated with an existing muIti-modal, four-steo model to produce a tool capable of analysing alternative ERP strategies hy using EMME/2,