Agent-based modelling became very popular in many fields of science over last few years. Multiagent systems (MAS) can simulate very closely behaviour of comprehensive, heterogeneous systems where another type of simulation fails. Traffic system is one of those complex systems. Microscopic traffic simulators based on MAS can model traffic system in realistic manner. But realistic simulation cannot be performed without detailed representation of the road network. There is necessary to describe roads and crossroads up to the level of traffic lanes including lanes restrictions. In this paper, an object-oriented road network environment for multi agent traffic simulation is present. The design of the environment based on the object structure was inspired by a standard for navigation data storage GDF. Additionally, road passport data from department of The Road and Motorway of the Czech Republic (Silniční databanka Ostrava) was used.