Research On The Impact Of Travel Information On Road Network Capacity

Road network capacity is a very important indicator of road system. It’s not only the base data of road planning and design, but also a significance parameter of traffic management. Based on road network capacity, we can obtain the saturation capacity and potential capacity of the network. We can also confirm the bottleneck sections and crosses. Transportation planning has to coordinate urban traffic, such as road traffic and rail transit. Furthermore, it has to achieve the coordination of transportation planning, urban planning and social economy. Since road network capacity is a very important aspect of transportation planning, it is fundamental to transportation development and social development. With the improvement of science and technology, more and more technologies have been introduced to transportation system. Advanced traveler information system (ATIS) is such a typical example. Traffic information published by ATIS affects travelers’ route choice behavior, thereby further affects the variation of road network capacity. So, it is necessary to study the impact of travel information on road network capacity.First, this paper will study the correlation theory of road network capacity, including the definition of road network capacity, the category of road network capacity and some factors that affect road network capacity. Then we introduce some major methods of road network capacity and evaluate them, respectively. We also study the previous ATIS theory and discuss the positive and negative effects of ATIS on travelers’ route choice behavior.Based on these above and the stochastic user equilibrium assignment theory, we will establish a bi-level programming model of road network capacity affected by ATIS information quality. We also establish a bi-level programming model of road network capacity affected by the penetration of ATIS. Heuristic algorithms based on the method of successive averages (MSA) are designed to solve the models. At the end, some numerical studies on a small road network are presented to demonstrate the impact of different levels of information quality and market penetration of ATIS on road network reserve capacity. The results show that both of the factors have great impacts on road network reserve capacity. The first example shows that, at first reserve capacity decreases with travel information increasing; when information parameter reaches a certain level, reserve capacity stays the same with travel information increasing. The second example shows that, reserve capacity decreases with market penetration increasing. A proper market penetration will lead to the link flows well distributed. But it has to be pointed that the increase of the market penetration has a decreasing contribution margin on equilibrium link flows.