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A Message from the JTRF Co-General Editors
The Spring 2007 issue begins the fourth year of publication by the publisher, the Upper Great Plains Transportation Institute. This issue contains the usual wide variety of transportation topics that distinguishes JTRF from other transportation journals. Topical areas include:
- Design of signal-controlled junctions for operational performance
- Stakeholder contributions to container port capacity expansion
- Effect of speed and speed variation on freeway crashes
- The relationship between quality of public transit service and customer satisfaction
- Did passenger fare savings occur after airline deregulation?
- Railroad capital stock changes, 1983-2005
- Determination of optimal winter speed limits
- The U.S. perspective on the United States-European Union open aviation area
In "The Influence of Geometry on Operational Performance of Signal Controlled Junctions," Dimitris Sermpis investigated the influence of geometry on the operational performance of signal controlled road junctions by using 16 experimental scenarios with different traffic and geometric characteristics. The characteristics were lane width, turning radii, and signal control strategy. Sermpis found that wider lane widths result in less delay under heavy traffic flow relative to narrow lane widths. He also discovered that a large turning radius results in less delay compared to a small turning radius, and that traffic responsive signal control results in less delay than fixed time control signals.
Michael J. Maloni and Eric C. Jackson examine stakeholder involvement in container port capacity expansion decisions in "Stakeholder Contributions to Container Port Capacity: A Survey of Port Authorities." The authors surveyed North American container port authorities to identify key port capacity factors and subsequent participation requirements by stakeholders including terminal operators, longshore labor, railroads, steamship lines, motor carriers, and government. Maloni and Jackson discovered port authority frustration with participation currently offered by all stakeholders, especially the federal government and railroads. The authors concluded that the results validate the requirement for a multi-stakeholder approach to port capacity expansion, and suggest the need for national freight policy and planning leadership in this area.
In "Freeway Speeds and Speed Variations Preceding Crashes, Within and Across Lanes," Kara M. Kockelman and Jianming Ma analyze the relationship between speed choice and crash occurrence on Southern California freeways. They used a variety of estimation methods including OLS, weighted least squares (WLS), and binomial regression models to find relationships among speeds, speed variation (measured as standard deviation) and crash likelihood, both within lanes and across lanes. All their models controlled for traffic density, weather, road lighting conditions, lane geometry, and road surface conditions. Kockelmen and Ma concluded that there was no indication of changes in speed patterns prior to crash occurrence.
Maria Morfoulaki, Yannis Tyrinopoulos, and Georgia Aifadopoulou examined the relationship between quality of public transit service and customer satisfaction in "Estimation of Satisfied Customers in Public Transport Systems: A New Methodological Approach." The objective of the paper is to identify factors that affect transit riders satisfaction and to develop a model to calculate the probability of customer satisfaction. To achieve the objectives the authors conducted a customer satisfaction survey in Thessaloniki, Greece, and used the survey data and operational characteristics of the public transit system to develop a multinomial logistic model. The model provided estimates of the factors affecting customer satisfaction with public transit services. The authors found that customer satisfaction can be improved by improving customer perception of waiting time, circumstances on board transit vehicles, frequency of service, on-time performance, and terminal safety.
In "Did Passenger Fare Savings Occur After Airline Deregulation?" David B. Richards questions the generally held belief that there were significant passenger fare savings and increased passenger traffic growth following airline deregulation. Using data from U.S. Department of Transportation agencies and the Air Transport Association, Richards breaks post-deregulation passengers and passengers fares into discrete distance intervals and compares the results to passenger and fare distributions prior to deregulation. He concluded that except for the period immediately before the terrorist attack in 2001 and continuing through 2005, there are limited demonstrable domestic system passenger fare savings.
C. Gregory Bereskin estimated a model of Class I railroad equipment and roadway capital stocks and the changes in their levels since 1983 in "Railroad Capital Stock Changes in the Post-Deregulation Period." The model is based on balancing investment and degradation of the capital stocks. Bereskin found that Class I railroads increased their absolute capital stock levels in the 1983-2005 period. This was the case for both roadway and equipment capital although roadway capital increased at a somewhat faster rate. He also noted that his method of estimating capital stocks may result in significant improvement over currently used measures of capital in both economic and regulatory costing models.
In "Optimal Winter Speed Limit," Suthipun Thanesuen and coauthors determine optimal winter speed limits for Hokkaido, Japan, through application of a cost analysis and analysis of the effects of road and traffic conditions. The authors initially conducted a cost analysis of travel time costs, vehicle operating costs, pollution costs, and accident costs to determine optimal average speed on the basis of minimum total cost. Then the effects of road and traffic conditions on optimal winter speed were calculated with regression analysis. The authors estimated optimal winter speed limits for four types of highways. They concluded that it is possible to apply their derived winter speed limits to all road and traffic conditions except for urban expressways.
Christian Hofer and Martin Dresner present a comprehensive analysis of current U.S.-E.U. aviation relations in "The United States-European Union Open Aviation Area: The American Perspective." Hofer and Dresner begin with a historical review of U.S.-European aviation relations, which is followed by a discussion of the North-Atlantic Open Aviation Area (OAA). The authors discuss the benefits of the Open Aviation Area including increased competition and lower prices, industry consolidation, and efficiency gains derived from increased market and firm size. This is followed by a discussion of the causes of the deadlock in U.S.-E.U. negotiations including foreign ownership of airlines, security concerns, U.S. protectionism, and access to London Heathrow airport. Hofer and Dresner then discuss the positions, interests, and actions with respect to the OAA of U.S. airlines, labor unions, the U.S. Department of Transportation, and the U.S. Congress.
Michael W. Babcock
Co-General Editor - JTRF
Kofi Obeng
Co-General Editor - JTRF
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