Study On The Bi-level Programming Model And Algorithm Of Lane Reservation For Hazmat Transportation In Port Cicies

The safety situation of hazmat transportation in China is severe,especially in some port cities with dense population and chemical industry,large traffic flow.The provision of reserved lanes is considered to be effective in preventing safety accidents and reducing potential safety hazards caused by mixed driving.It has become a realistic choice to reduce the risk of hazmat road transportation,but may make ordinary lanes more crowded.Based on this,in order to achieve the tradeoff between transportation cost,risk,and impact on the normal traffic,this paper studies the model and algorithms of lane reservation for hazmat transportation in port cicies to solve the lane reservation selection problem and hazmat vehicles routing problem in a road network with reserved lanes.Based on the theory of moving bottleneck,this paper analyzes the interference between hazmat vehicles and social vehicles under the condition of mixed traffic,demonstrates the necessity of the diversion of hazmat vehicles and social vehicles to reduce the interference between this two traffic flows,which lays the foundation for the next study on the implementation of the resvered lane strategy in hazmat transportation.Combined with traffic flow theory,the impact of on normal traffic is quantified,and the risk of hazmat vehicles driving on a reserved lane.And a two-level planning model for the lane reservation for hazmat transportation is constructed.The upper-level plan optimizes the layout of the reserved lanes for hazmat vehicles with the goal of minimizing transportation risks and minimizing the impact on normal traffic.The lower-level plan models hazmat transportation tasks with multiple OD pairs,and selects the best path on the optimized road network.Then based on the nature of NP-hard in bilevel programming,two-hybrid metaheuristic algorithms based on the particle swarm optimization algorithm and the genetic algorithm,respectively,and a precise algorithm based on enumeration method,are proposed to solve the bi-level model.Finally,to prove the effectiveness of the model and algorithms,the computational results on instances are compared and sensitivity analysis on the key parameters is presented.The results show that:1)The bi-level model can effectively reduce the total risk of the hazmat transportation while considering the interests of hazmat carriers and ordinary travellers.2)Both metaheuristic algorithms are effective methods for solving this problem,and the method based on the particle swarm optimization algorithm requires a shorter computation time,whereas the method based on the genetic algorithm shows more advantages in optimality.3)The utilization rate of reserved lanes increases with increasing number of tasks.Nevertheless,this does not suggest that the greater the utilization,the better the effect of risk reduction.Once the proportion of hazmat vehicles is excessive,the advantage of reducing the risk of the reserved lanes gradually decreases.(3)To a certain extent,the increase in the utilization rate of reserved lanes can improve its effectiveness in reducing risks,but as the utilization rate continues to rise,especially when(?),the advantage of reserved lanes in reducing risks will gradually decrease.