Alternative marginal-cost pricing for road networks

In the literature, several studies have algebraically characterized the set of toll vectors or patterns that, when added to a user equilibrium problem, its solution would be system optimal. Toll vectors in this set are termed “valid.” While the toll vector commonly advocated in the literature, i.e., one that equates the toll on each link to its marginal external cost, is always valid, other valid toll vectors generally exist and many leave some utilized links in the network untolled. On the surface, this may appear unreasonable and seems to violate the principle of marginal-cost pricing. This note shows that, when travel demands are elastic, all valid toll vectors satisfy this principle, in that the total tolls for each path equals the congestion externality an additional traveler on the path imposes on others.     

Pareto-improving and revenue-neutral congestion pricing schemes in two-mode traffic networks

This paper studies a Pareto-improving and revenue-neutral congestion pricing scheme on a simple two-mode (highway and transit) network: this scheme aims at simultaneously improving system performance, making every individual user better off, and having zero total revenue. Different Pareto-improving situations are explored when a two-mode transportation system serves for travel groups with different value-of-time (VOT) distributions. Since the congestion pricing scheme suggested here charges transit users negative tolls and automobile users positive tolls, it can be considered as a proper way to implement congestion pricing and transit subsidy in one step, while offsetting the inequity for the poor. For a general VOT distribution of commuters, the condition of Pareto-improving is established, and the impact of the VOT distribution on solving the inequity issue is explored. For a uniform VOT distribution, we show that a Pareto-improving and revenue-neutral pricing scheme always exists for any target modal split pattern that reduces the total system travel time.     

航权开放与出口导向型服务产业发展——基于三亚旅游业发展的实证分析

为提高服务业对外开放水平、加快出口导向型服务业的国际化发展,越来越多的地方政府将航权开放提上了议事日程。本文利用我国最早开放客运航权的试点地区,海南三亚1994年至2010年间的旅游业统计数据,采用动态计量模型分析并解释航权开放对旅游业发展的影响,得到以下结论:航权和签证等消费者移动壁垒的开放进程,应与出口导向型服务业的发展水平相适应,而不是"越快越好、一放就灵";当出口导向型服务产业尚处于粗放型发展的初级阶段时,过早实施全面开放政策有可能导致客源市场结构的低端化发展、粗放型发展模式的增强循环和产业国际分工地位下降等后果,因此航权开放的最优决策应是以产业要素升级和管理体制改革进程为依据,渐进、有序地逐步开放。     

TRAFFIC LIGHTS: WEAPONS OF MASS DISTRACTION,DANGER AND DELAY

Since my 2006 article in Economic Affairs proposing traffic system reform, there has been a growing interest in the subject. Trials in deregulation have produced the results that students of the subject predicted – congestion‐free roads and sociable interaction between road‐users.     

Downtown curbside parking capacity

Current debates on downtown parking policy have been concentrating on downtown parking pricing, while overlooking downtown parking capacity. This paper focuses on how much curbside to allocate to parking when the private sector provides garage parking. In the first-best optimum, no cruising for parking occurs, and only curbside parking is provided when demand is low relative to street capacity, both curbside parking and garage parking are provided when demand in intermediate, and only garage parking is provided when demand is high. In the second-best optimum where curbside parking is underpriced, cruising for parking occurs only when both curbside and garage parking are both present. As the fee differential between garage and curbside parking increases, cruising for parking becomes more severe, and the range of demand levels over which curbside and garage parking are both present shrinks and eventually disappears.     

城市轨道交通项目设计管理模式分析

本主要从城市轨道交通项目设计工作的特点出发，介绍了目前常见的两种设计管理模式，并对这两种模式进行对比分析。在此基础上，进一步探讨设计总体管理模式在工程实例中的运用。     

Buffering in evacuation management for optimal traffic demand distribution

This paper presents a new framework for managing congestion during emergency evacuations. The algorithm allows a long link of the network to be used as a buffer to keep the traffic flow moving in. Concurrently, a detour trigger time is estimated to keep the traffic under-saturated in the buffer zone and minimize the total travel time. The integration algorithm presented in this paper is an efficient mathematical solution for travel time cost calculation. A case study is presented to demonstrate the efficacy of the traffic demand buffering strategy developed in this research for managing the evacuation flow.     

Bounding the efficiency of road pricing

This paper deals with the following question associated with congestion pricing in a general network with either fixed or elastic travel demand: what is the maximum efficiency loss of a general second-best pricing scheme due to inexact marginal-cost pricing in comparison with the first-best pricing or system optimum case? A formal answer to this question is provided by establishing an inefficiency bound associated with a given road pricing scheme. An application of the methods is provided for the practical trial-and-error implementation of marginal-cost pricing with unknown demand functions.     

基于分形理论的铁路客货运量预测

在阐述分形基本理论和分析铁路运输时间序列分形特性的基础上,基于变维分形理论对铁路客货运量进行预测。根据铁路运量分形预测原理及步骤,以全国铁路运量预测为例进行分析,计算得到铁路2012年、2015年、2020年的客货运量,以及2010—2020年的客货运量增长率,并对预测结果进行了具体分析。     

Development of zone system for macro-level traffic safety analysis

Various geographic units have been used in macro-level modeling. Amongst these units, traffic analysis zones (TAZs) have been broadly employed in many macroscopic safety studies. Nevertheless, no studies questioned the validity of TAZs for crash analysis at the macro-level crash modeling. In this study, we point out several possible problems of TAZs as spatial units for macroscopic safety studies. Current TAZs with homogenous crash rates were combined into new single zones. Then we created ten new zonal systems by different zone aggregation levels. The optimal zonal scale for traffic safety analysis zones (TSAZ) was determined using the Brown-Forsythe test. It was found that the zone system with about 1:2 aggregation was the optimal zone system for macroscopic safety modeling. Thus we develop what we call traffic safety analysis zones (TSAZs) that has the potential of reducing several possible problems of TAZs. Also it was shown that TSAZ based models had better fit compared to TAZ based models.