Minimizing the response time to incident is one of the important objectives of traffic incident management. Extremely high demand for freeways has become a major obstacle for citizens' travel in China during National Holidays. Incident frequency witnessed quite a few times increase as compared to normal days. Additional emergency service should be arranged to provide instant help to reduce traffic delay and get injured casualties cured. Under the congested traffic status on freeways during high demand, incident response dispatching strategy is more appropriate for vehicle patrolling operation. Optimal location of these additional emergency service response units is important for freeway incident management under extremely high demand environment. Accident occurrence probability should be various along the different freeway segments but received scant modeling for optimal strategy. Towards this gap, this paper aims at a model formulation for allocating additional emergency service in response to freeway accidents under highly congested traffic environment. Continuous accident probability function is induced indicating the propensity of accident occurrence. The numerical scenario result showed that the model formulation improved the optimization of emergency response unit and saves the response time to the freeway accident a lot. Key words: Extremely high demand, freeway accident, additional emergency service, optimal location

CICTP