Narrow Results

In order to further reveal the law and characteristics of on-ramp traffic flow into the main line of expressway road and make up for the deficiency of traditional inflow model which cannot evaluate the state of merging area, the coupling theory in physics was introduced. First of all, “gap acceptance” model was adopted to describe the operation law of merging area, and the relationship between important parameters such as flow rate and headway was analyzed by using discrete probability function. Second, coupling degree and coupling coordination degree were put forward, after analyzing the characteristic under the premise of the merging area, using a large amount of measured data regression analysis of the traffic, location speed and the headway of parameters in the coupling. The coupling theory was modified, the coupling function evaluation model of confluence area was established, and the interaction and influence between main line and ramp system were quantitatively analyzed and evaluated. Finally, the model is verified by the actual observation data of Shanghai expressway. The results indicate that in the early peak period, the coupling coordination degree is about 0.36 and 0.4, which is in a moderate coordination stage. During the peak flow period, the coupling coordination degree is only 0.28, which is in a low degree of coordination coupling and the system is relatively disordered. In nonpeak hours, the coupling coordination degree is around 0.83, which is in an extremely coordinated state. The error between the flow calculated by the coupling theory and the data observed in the field is generally 4.2%–12.8%, which indicates that the results of the running status evaluation of merging area by using this model are reliable.

In Japan, electric vehicle (EV) is spreading, because EV has several advantages compared with gasoline car. However, EV has two main disadvantages, shorter cruising range and longer charging time. These disadvantages may cause a serious problem on an expressway, because the queue of EV waiting for charge may be long, if enough chargers are not placed at charging places. It is important to estimate the number of chargers in a charging place to avoid the long queue. This paper proposes a model to estimate the number of chargers used by EV. In this model, it is assumed that the driver knows the charge level of EV and decides to charge at charging places according to the type of charging place and charge level.

Transportation is the most basic element in the development of tourism, with expressways being the main channel for tourism transportation in the era of driving tours. The relationship between transportation and tourism development has always been one of the hot topics in tourism geography study. Since the expressway service area is the main node of tourist service facilities in the expressway transportation network, we conducted a field research on 125 service areas and 177 tourist attractions in Guizhou Province, and obtained relevant data. By using the centrality measures for social network analysis, and combining the kernel density analysis with bivariate spatial autocorrelation analysis, this paper explores the centrality characteristics of expressway transportation network, the spatial distribution regularity of tourist attractions, and the spatial coupling between them. The main study conclusions are as follows: (1) The expressway service areas in Guizhou Province gradually decrease from a single core to the periphery. (2) The spatial distribution of tourist attractions presents a weak circular structure with multiple cores in a scattered manner, and the regional differences are apparent. (3) There is positive spatial correlation between the expressway networks and tourist attractions. The spatial coupling between the expressway transportation network and tourist attractions can be divided into four types of clusters: high–high cluster, high–low cluster, low–high cluster, and low–low cluster, with high–high and low–low clusters as the main types. The high–high cluster is the area with the best coupling effect and the most mature tourism. The high–low and low–high clusters have a mismatch between transportation and tourism resources. For such clusters, the spatial coupling can be realized by changing the functions of the service area or improving the quality of the tourist attraction. They have great development potential. The low–low cluster is far away from tourist attractions and markets, thus it has a small value of tourism development, and it is the critical area for future improvement. The conclusion of this study can provide a theoretical basis and scientific suggestions for promoting integrated and coordinated sustainable development of transportation and tourism.