Examining the spatial-temporal relationship between urban built environment and taxi ridership: Results of a semi-parametric GWPR model

With the advance of intelligent transportation systems (ITSs) and data acquisition systems (DASs), it becomes possible in recent to explore the determinants of urban taxi ridership using multi-source heterogeneous data. This paper aims to use floating car data, points-of-interests (POIs) data and housing-price data to assess the influence of the built environment on taxi ridership. Within a scale of 0.5 km grid, critical indicators related to the economic aspect, intermodal connection, and land use factors were obtained using the multi-source data in Shanghai. To capture the spatial and temporal heterogeneity, Semi-parametric Geographically Weighted Poisson Regression (SGWPR) models are built over different time dimensions. It is found that SGWPR models result in higher goodness-of-fit than the generalized linear models. More importantly, the results show the impacts of built environment factors on taxi demand are highly heterogeneous, positive or negative in different city areas, reflected in the significant temporal variations of the effects. Overall, these findings suggest that the built environment factors have significant impacts on urban taxi demand, and the spatial context should not be ignored. Findings in this paper are expected to help better understand the relationship between urban taxi demand and built environment factors, improving the service level of the urban taxi system, and offering valuable insights into future urban and transportation planning.     

Determinants of route choice behavior: A comparison of shop versus work trips using the Potential Path Area - Gateway (PPAG) algorithm and Path-Size Logit

This paper presents an in-depth comparison of route choice models for work and shop vehicle trips—with emphasis on the interactions between route attributes and individual characteristics—to better understand the route choice determinants that are assumed to vary by trip purpose. Insights into the route choice behavior involving two dominant vehicle trip purposes—work and shop trips—will help in the design of traffic facilities and implementation of measures to influence route choice in the desired direction.In this study, we show that the utility and scale parameters for separate models of work and shop trips differ by direct comparison using a sequential scaling estimation method and likelihood ratio tests, and highlight the differences in route choice behavior by considering the interaction of route attributes and individual characteristics using Path-Size Logit modeling. In the process, we used Potential Path Area - Gateway (PPAG) algorithm—that generates feasible route choice sets for route choice modeling from GPS trajectories of observed routes.The results show that, indeed, route choice behavior varies by trip, which suggests that drivers attach value to route choice determinants relative to trip purpose. The inclusion of interaction terms in model specifications further indicates that work route choice behavior tends to be restrictive compared to the nonrestrictive route choice for shop trips—a generalization consistent with the mandatory and discretionary nature of work and shop trips, respectively. Specifically, individual characteristics such as personal income, age, gender, tenure, household size, and access to public transit affect route choice behavior.     

The potential economic viability of using the Northern Sea Route (NSR) as an alternative route between Asia and Europe

The Arctic Ocean has been greatly affected by climate change. Future predications show an even more drastic reduction of the ice cap which will open new areas for the exploration of natural resources and maritime transportation. Shipping through the Arctic Ocean via the Northern Sea Route (NSR) could save about 40% of the sailing distance from Asia (Yokohama) to Europe (Rotterdam) compared to the traditional route via the Suez Canal. However, a 40% reduction in distance using the NSR does not mean a corresponding 40% in cost savings due to many factors, including: higher building costs for ice-classed ships, non-regularity and slower speeds, navigation difficulties and greater risks, as well as the need for extra ice breaker service.The main purpose of this study is to investigate the economic potential of using the NSR as an alternative route between Asia and Europe by taking all the main factors into consideration. It focuses on economic aspect of the NSR, therefore navigation/ environmental/cultural/legal issues are not discussed.The economic study is conducted by a case study in which 4300 TEU container ships (both non-ice classed and ice classed) are employed to make year round service. The annual profit gained from regular service by a non-ice-classed ship via the Suez Canal for the entire year is compared to the annual profit gained from an ice-classed ship taking the NSR during the navigable months and Suez Canal for the rest of the year. There are three factors that influence the NSR the most: the navigable time of the NSR, Russian NSR fees and bunker prices. To make this study flexible, three scenarios for navigable time, three scenarios for Russian NSR fees as well as three scenarios for bunker prices are proposed. These assumptions are all combined with each other and the profit under each condition is then calculated. The overall comparison is made in order to see under which conditions the NSR is competitive with the Suez Canal.