Recently, train traffic management operation is being complex because of congested train schedules, mutual line operations and various kinds of cars/classes. So it is necessary for decreasing operator's workload and raising his skill to help his work by computer systems. A research in train traffic simulation has been done by several approaches. But the approaches have focused on simulating only physical constraints such as running velocity of cars or signaling equipment and haven't dealt with atypical constraints such as speed regulation under bad weather condition. In this paper, we proposes a modeling method of the atypical constraints and an expandable simulation architecture for adding the constraints. Being evaluated using our prototype system, it is shown that our approach can assemble simulation logics for various kind of constrains handily and simulate effects of the constraints precisely keeping practical response.