Parking subsidies and travel choices: Assessing the evidence

This article reviews empirical studies of how employer-paid parking affects employees' travel choices. A strong effect is found: parking subsidies greatly increase solo driving. When employers reduce or remove parking subsidies, a significant number of solo drivers shift to carpools and/or transit. This conclusion is based on studies of parking subsidies in a variety of circumstances, including central city and suburban areas, private and public employers, and clerical and professional employees. Three measures are developed to compare changes in commute patterns: changes in the share of solo drivers. changes in the number of autos driven to work per 100 employees, and the parking price elasticity of demand for solo driving. The studies reviewed here show that 19 to 81 percent fewer employees drive to work alone when they pay for their own parking. Because 90 percent of American commuters who drive to work receive employer-paid parking, these findings are significant for designing transportation policies to reduce air pollution, traffic congestion, and energy consumption.     

Rochdale remembered: a personal memoir

The Committee of Inquiry into British Shipping, chaired by Viscount Rochdale, reported in May 1970, over 25 years ago. It is therefore appropriate to consider how it come to be established, its working and the validity of its ideas. As economic adviser to the Committee. I attended almost all its meetings, though the Secretary, Donald Simpson, wrote most of the Report     

Factoring a real value of cargo in port investment and funding decisions

Ports are marine gateways to economic activities. Ports’ ability to perform services depends on their facilities, harbor conditions, and other factors. Generally, ports have control over their facilities but must compete for funding to improve them. As for waterways, in the U.S., a Harbor Maintenance Trust Fund was established to fund dredging, which levies a 0.125% cargo value tax on most shippers using U.S. coastal and Great Lakes harbors. Yet, commonly, a gross tonnage metric is used to allocate the fund’s resources, resulting in under-maintenance of some harbors. This, reportedly, deters additional port funding and hinders valuable commerce. Supplemental economic metrics, such as value of commerce or cargo, can improve port financing decisions, but such data is not readily available. Container ports collect cargo value data in nominal terms, but bulk ports do not. When making economic decisions, however, real values must be used. Further, when allocating resources, decision-makers must be able to assess ports over time and relative to each other. Conforming to these criteria, this paper develops three port financing indicators based on a real value of cargo and illustrates their calculations using the U.S. Port of Duluth-Superior as a case study.     

驾驶模拟在公路安全设计与运行中运用的研究

随着日益增长的交通需求,为了能够获得最高性能的公路交通系统,驾驶任务变得越来越复杂,公路设计和建设中考虑人的因素也变得更为重要.能否成功引进新的驾驶支持体系、动态的交通管理系统或者复杂的道路设计,主要依赖于人们是否能够以及有多大意愿去适应这种发展.为此需要了解人们在复杂的动态驾驶任务环境中将会做出怎样的反应.该文在简单地介绍完TNO驾驶模拟器设备后,又介绍了有关利用先进的人机互动驾驶模拟器研究人的驾驶行为来进行公路设计和建设.文中通过几个公路设计和交通运输行为研究的例子,说明了驾驶模拟器研究对安全有效地进行公路设计与运行运用具有特殊的价值.     

Effects of changing highway design speed

In an effort to increase the operational efficiency of highways, South Korea has been increasing its design speed recently. However, the use of higher design speed will also increase construction costs. Moreover, increasing the design speed is expected to have an impact on safety. Hence, there is a strong need to demonstrate that the benefits outweigh the cost of having a higher design speed. This study surveyed a sample of design engineers to determine their awareness of the consequences of increasing design speed and their assessment of the right design speed for an actual rural arterial road. In addition to the survey, a case study of three recently upgraded highways was conducted to determine the changes in traffic volumes, speeds, travel times and accidents. The construction costs associated with the upgrades were also reported. Copyright © 2011 John Wiley & Sons, Ltd.     

Enhanced, multi criteria based site selection to measure mobile source toxic air pollutants

A multi-criteria-based site selection process that was developed for the Las Vegas near-road study is used to select the most appropriate near-road measurement sites in the Detroit area. The study measures particulate matter with aerodynamic diameters ?2.5 μm and mobile source air toxic compounds, and to document the rationale for selecting or rejecting specific sites. An application of this multi-criteria decision analysis may be the recent US Environmental Protection Agency rule requiring the siting of NO₂ monitors within 50 m of major roads as well as siting for the measurement of community-wide NO₂ concentrations.