Modeling Morning Commute with Different Kinds of Activities Based on Bottleneck Model

Morning commute problem has always been concerned by researchers in transportation research field.For the bottleneck existing in the road network between home and school,this paper studies the household travel with different kinds of activities,i.e.,home-school-home trip and home-school-workplace trip.Individuals just send their children to school and then go home,which is named school travel.Individuals need to send their children to school firstly and then go to work,which is named household travel.Firstly,according to the proportions of two types of travelers and school-work start time difference,the possible equilibrium cases are solved and the conditions for the occurrence of each case are revealed.Different from the traditional bottleneck model with a unique equilibrium traffic pattern,the mixed travel case has six possible equilibrium traffic patterns.Secondly,the cost of traveler is analyzed for all possible equilibrium traffic patterns.Result shows that equilibrium trip costs of two types of travelers are more sensitive to the number of travelers in that class than the number in another class in all possible equilibrium cases.Finally,the influence of school-work start time difference on the total travel cost is discussed.Result shows that the total system travel cost can be reduced by appropriately adjusting the difference of school-work start time.