Research Reports

Persistent link for this collectionhttps://hdl.handle.net/11299/241

The Center for Transportation Studies' research reports present the results of University of Minnesota projects in all areas of transportation research.

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Now showing 1 - 20 of 1296

An Examination of the Potential to Reduce the Cost of an Underground LRT Alignment through Geologic Planning and Technological Innovation: Phase I
(1987-09) American Underground-Space Association
The question of whether Twin Cities Metropolitan Region transportation needs should be served by fixed rail transit has been debated for many years. It appears that the issue may be approaching resolution as a result of the formation of the Regional Transit Board (RTB) and recent activity on the part of Hennepin County in forming a Regional Rail Authority and moving ahead with planning activity. Some important questions about light rail (LRT), such as the capacity of the system, are being answered, but others are not resolved. One of these is whether to site portions of a light rail system underground. While many decisionmakers endorse the worth of an underground alignment in at least the most densely developed urban areas, the cost versus benefit to construct underground versus a surface alignment has been an important factor.
Urban Congestion Reduction for Energy Conservation: Control Strategies for Urban Street Systems: A State of the Art: Final Report
(1988-01) Hajjiri, Samir A.; Stephanedes, Yorgos J.
The primary objective of this study is to acquire an understanding of the current state-of-the-art of traffic signal control strategies at urban street systems. Control of traffic signals is by far the most common type of control at heavily trafficked intersections in urban areas. Inefficient use of the transportation system results when traffic signals are set without the aim of optimizing them. The byproducts of such situations include greater fuel consumption, increased vehicle emissions, increased travel time, higher accident rate, and less reliable services.
Urban Traffic Monitoring, Navigation, and Guidance to Alleviate Urban Traffic Congestion
(1988-03) Chang, Kui-Kuo; Stephanedes, Yorgos J.
Traffic congestion in urban area seems to be rapidly spreading in space and in time. A few years ago, roads surrounded the central business district of any metropolitan areas had hardly any traffic at all. But now, thousands of commuters crowd in there and try to find shortcuts from their suburban homes to their suburban office destinations. Traffic congestion is spreading to the entire highway network instead of the main radial corridors from downtown. Similarly, the traditional rush hours during the morning and afternoon in the urban area disappeared and have been replaced by a high plateau rush hour which continues from early morning to evening.
Transportation and Economic Development
(1988-07) Stephanedes, Yorgos J.
This report summarizes the results of a project undertaken by a University of Minnesota team for the Minnesota Department of Transportation (Minnesota DOT) to determine the existence and extent of relationships between transportation and economic development (in particular, employment) in Minnesota. The interdisciplinary team was directed by the Department of Civil & Mineral Engineering and included experts from Civil & Mineral Engineering, Geography, Economics (both Twin Cities and Duluth campuses), Applied & Agricultural Economics, Industrial Engineering & Operations Research, and Regional Economics.
Case Study: Downtown Seattle Transit Project
(1988-09) Center for Transportation Studies
The Downtown Seattle Transit Project is a $412 million construction project undertaken by Seattle Metro, which centers on a 1.3 mile-long tunnel under downtown Seattle. This report presents an overview of the transportation system improvements under construction in Downtown Seattle. The purpose of the report is to provide an analysis of one of the options available to help reduce CBD congestion in major cities throughout the country.
Minnesota transit laboratory: phase 1 conclusions: improving transit service
(1989) Stephanedes, Yorgos J.; Doumbia, Bangali
The desire to increase the attractiveness and use of transit has led the Minnesota Department of Transportation, the Center for Transportation Studies, and the Department of Civil and Mineral Engineering at the University of Minnesota to set up a Laboratory for developing improved service and encouraging innovation in transit. Prior to seeking improvement of transit operations and the attractiveness of public travel, the problems of the transit industry had to be clearly defined. To that effect, an initial set of eight problem areas was defined and prioritized on the basis of short- and long-term by a group of local experts. However, as seeking solution to all the problems hence defined would be a most demanding task, it was desirable to reduce the set to a more manageable size that included the problems that were well defined, important, feasible and desirable for analysis and solution in Minnesota and elsewhere. To conduct this analysis, a well known and proven methodology, the Delphi Technique, was used. The findings of the Delphi procedure indicate a prioritization that is, in principle, different from what was initially suggested by the group of local experts. Both groups - the Delphi participants and the local experts ? did concur on the ratings of a few problems (e.g., EFFECT OF COLD CLIMATE). The results of the Delphi procedure and the suggested prioritization of the local experts are exhibited on the following page.
Transportation of Energy in Minnesota: Review and Analysis
(1989-06) Harper, Donald V.
The purpose of the study reported on here was to investigate and analyze the energy transportation system in Minnesota in order to identify what the system consists of and how energy sources' are transported to and within the state, and to evaluate the system and to make recommendations for state policy on the matter. It is hoped that the report will be useful to producers, distributors, and users of energy and those who perform energy transportation service, and to government agencies responsible for promoting and/or providing and/or encouraging private investment in transportation facilities in Minnesota.
The Impact of the Use of Just-in-Time on the Use of Inbound Transportation by Manufacturers
(1989-11) Harper, Donald V.; Goodner, Karen S.
Transportation is a critical element in any JIT system and several transportation practices can be affected by the need to support a manufacturer's inbound JIT system. These include increased importance attached to inbound transportation, a shift in who has control over inbound transportation, the size of and frequency of shipments, the lengths of haul, the mode and carrier choice, the number of carriers used, and vehicle utilization. In addition, energy consumed in transportation and transportation costs can be affected. The objectives of the mail and personal interview study reported on here were, first, to determine the extent to which manufacturers in Minnesota and Wisconsin have adopted the JIT concept for inbound movements and what kinds of firms they are in terms of size, products produced, and plant location. The second objective was to determine, for those manufacturers included in the study, why they did or did not adopt the JIT philosophy. The third objective was to determine to what extent the implementation of inbound JIT caused a change in the use of transportation. The study was a preliminary study in that it was intended to provide information that could be used as a foundation for a more detailed study later.
Transit System Monitoring and Design
(1990-01) Stephanedes, Yorgos J.
Statistical techniques were developed for extracting the most significant features (indicators) from a transit system data base, and classifying proposed and existing transit systems according to the selected features. The data base was constructed by using information from all previous years available by the Mn/DOT, the Census and other sources to be used in classifying transit systems. The data base emphasized the use of raw characteristics of the operating system and the area socioeconomics. The feature extraction was done so that the minimum number of features were extracted that can be used for classifying the transit systems with maximum accuracy. The classification method was designed around the data base and is flexible so that it can use future data to update the data base at minimum cost. The transit system patterns, resulting from the classification method, were identified according to need and performance, and the main characteristics were specified for each pattern. These characteristics and descriptions identifying each pattern determines whether it should be modified. A controlled experiment was required to test the classification method. A randomly selected part of the data was classified by the method, and then the unselected data was treated as a control group for the experiment. After the experiment a percent of misclassifications was calculated.
The Use of Driving Simulation for the Assessment, Training and Testing of Older Drivers
(1990-01) Hancock, Peter A.; Caird, J. K.; White, H. G.
With the lowering of the birth rate over the last decade and a half, and the increased life expectancy associated with improving health care, the United States is undergoing a radical aging of its populace. This change in demographic structure is embedded in a society experiencing clear and rapid advances in its technological capability (Abend & Chen, 1985; U.S. Congress, 1985; Tobias, 1987). One ramification of these combined developments is that expectations of activity and lifestyle change rapidly across successive cohorts. Typically, each sequential cohort expects to retain access to progressively wider ranges of activity which have become characteristic of their respective lifestyles. Contemporary and future cohorts will expect continued access to the privilege of autonomous mobility, typically through the use of the automobile (Wachs, 1988; Waller, 1972). This aspiration generates a conflict between two powerful and somewhat antagonistic societal forces. On one side is the traditional and expected freedom that emanates from owning and operating a personal automobile. On the other is the potential and actual safety hazards associated with the actions of an aging central nervous system having to cope with progressively more complex and demanding driving environments (Federal Highway Administration, 1986). The potential resolution of this conflict lies in the use of a systems approach as a framework to apply Human Factors principles to improve the driving environment, the vehicle, and facilitate the capabilities of the driver. Unfortunately, there is little research available that is specifically directed at the Human Factors problems faced by aging drivers with regard to design of automobiles, roadways, and roadway communication symbols (Forbes, 1985; Staplin, Breton, Haimo, Farber, & Byrnes, 1986; Yanik, 1989). Consequently, there is a fundamental need for research efforts in this area. It is one facet of this systems-based strategy (Doebelin, 1980), namely the use of simulation in training, testing, and evaluating the older driver, that is the focus of the present report.
Effect of Creep and Coldness-Induced Shrinkage on the Performance of Laminated Timber Bridge Decks
(1990-01) Seavey, Robert; Erickson, Robert
The purpose of this research has been to analyze the effect of creep on stress laminated timber bridges where creep refers to the time-dependent deformational behavior of the wood. Of particular interest has been the cause of stress loss in stress laminated bridges. During the course of this research, another important factor which affects the level of rod stress in timber bridges was discovered: coldness-induced shrinkage of wood. After the construction of a stress-laminated bridge in northern Minnesota in October, 1988, a significant reduction in rod stresses was noted during a particularly cold period in December of that year. Proper rod stresses are needed for a stress-laminated bridge to perform as an orthotropic plate whereby there is a high degree of load sharing between adjacent laminae. An abrupt reduction in rod stress due to external temperatures poses an important design and service issue for timber bridges.
Alternatives to the Automobile: Transport for Livable Cities
(1990-01) Lowe, Marcia D.
The problems created by overreliance on the car are outweighing its benefits. A new, more rational approach to transportation is needed, one that puts the automobile in its rightful place as one among many options. Making drivers pay more of the true costs of automobile use would hasten the shift to public transportation, cycling and walking. In both industrial and developing countries, careful urban planning can help meet future transportation needs by minimizing the demand for travel. But creating sustainable transportation requires bold policy moves.
Wide Area Detection System (WADS): Image Recognition Algorithms
(1990-02) Michalopoulos, Panos; Johnston, S. E.; Fundakowski, R. A.; Fitch, R. C.
Vehicle detection through machine vision is one of the most promising advanced technologies available today for dealing with the problem of urban traffic congestion. In this project an existing Wide Area Detection System (WADS) was improved for performing detection under all weather, traffic, and artifact conditions (e.g. shadows, reflections, lightning, etc. As a result of this and other related research efforts by the same team, a real-time (instead of the initially envisioned off-line) multispot breadboard WADS system was developed, installed, tested, and demonstrated in several real-life situations. The system can simultaneously detect traffic at multiple points within the field of the camera's view and emulates loop detectors. The test results to this point suggest high accuracy levels, comparable to loop detectors, while speed measurement appears to be more accurate than loops. Live demonstrations and off-line presentations generated the enthusiasm and support of practicing engineers and public officials. They also suggest that the WADS system developed in this project is the most advanced one available today. Despite this, further work remains to be done prior to production. This includes extensive field testing and validation as well as implementation of applications possibly through demonstration projects. This report describes the WADS algorithm development and testing and makes recommendations for field implementation of the technology.
Vibration Spectroscopy for Rigid Pavement Joint Assessment
(1990-08) Palmieri, Lucio; Krauthammer, Theodor
This study was conducted with the aim of improving the state of knowledge on the behavior of joints in concrete pavements, and to explore the feasibility of developing a non-destructive testing technique based on the frequency response of dynamically loaded joints. One of the objectives of the present study was to experimentally investigate the existence of a relationship between load transfer capacity of a joint in rigid pavements and its dynamic response. the experimental study involved the application of an impact testing approach for the evaluation of two test systems. One system represented an ideal condition of full load transfer across a joint, while the other system was used to simulate variable load transfer conditions. Acceleration-time histories captured from both sides of the joint, under short load pulses, were used for analysis both in the time and frequency domains. These results provided a comprehensive description of the joint response characteristics, and enabled the derivation of a clear relationship between the response frequencies and the joint's shear transfer capabilities. These results may be used as the starting point for the development of a precise non-destructive testing method for a wide range of cases in which shear transfer across discontinuities in concrete systems is a principal load resisting mechanism. Specific conclusions and recommendations on future developments have been provided.
Numerical Assessment of Three-Dimensional Rigid Pavement Joints Under Impact Loads
(1990-08) Koubaa, Amir; Krauthammer, Theodor
This study was conducted with the aim of improving the state of knowledge on the behavior of joints in concrete pavements, and to explore the feasibility of developing a non-destructive testing technique based on frequency response of dynamically loaded joints. One of the objectives of this study was to numerically investigate the existence of a relationship between load transfer capacity of a joint in rigid pavements and its dynamic response. The approach adapted for the present study is based on a numerical model which accurately represents the mechanism of shear transfer in reinforced concrete members implemented it in a commercially available finite element code. That tool is then used for the analysis of two models which consisted of various joint conditions. One model represented an ideal condition of full load transfer across a joint, while the other model was used to simulate variable load transfer conditions. The results obtained are analyzed in the time and frequency domains. These results provided a comprehensive description of the joint response characteristics, and enabled the derivation of a clear relationship between the response frequencies and the joint's shear transfer capabilities. The results may be used as the starting point for the development of a precise/non-destructive testing method for a wide range of cases in which shear transfer across discontinuities in concrete systems is a principal load resisting mechanism. Specific conclusions and recommendations on future developments have been provided.
Just-in-time and the use of transportation by Minnesota and Wisconsin manufacturers
(1991-02) Harper, Donald V.
The objectives of the study were to determine (1) the extent to which manufacturers in Minnesota and Wisconsin have adopted the JIT concept for inbound or outbound movements; (2) what kinds of firms can successfully use JIT in terms of their size, plant location, products produced, and type of manufacturing (repetitive or non-repetitive); (3) for those manufacturers that have adopted the JIT philosophy, what their reasons were for doing so and, for non-users of JIT, why they had not done so; and (4) to what extent the assumptions concerning the use of transportation in a JIT environment are supported by the experience of manufacturers in Minnesota and Wisconsin, i.e., what was the effect of their participation in JIT on their use of transportation. The study, conducted in 1989-1990 followed a preliminary study conducted in 1988-1989.
Corrosion Investigation of Reinforcing Bars in Pavements and Bridge Decks Part II: Chloride Penetration/Rebar Corrosion Mechanisms
(University of Minnesota, 1991-02-19) Jang, J.W.; Iwasaki, I.
The main factors that influence the initiation and propagation of rebar corrosion in concrete are concrete properties, aggressive corrosive elements from the environment and concrete, and defects of the reinforcing material. The presence of chloride ion appears to be the dominant cause for rebar corrosion in concrete. Rebar corrosion is complex and the basic mechanisms of individual factors are not well understood because of the complex nature of physical and electrochemical factors and because of their interdependence. A visualization technique was developed for use in our laboratory for the determination of chloride ion distribution and concentration near the reinforcements in concrete. A galvanic current measurement technique was developed for estimating the corrosion rates of rebars in simulated concrete solutions and for investigating the effects of relevant parameters that may be responsible for macro-cell corrosion on rebars as a function of chloride ion concentration. The corrosion mechanism of rebars was explored by using the galvanic current measurement method as well as by using optical and scanning electron microscopy. The compounds that combine the properties of a corrosion inhibitor and a surfactant were explored for retardation of rebar corrosion. Organic compounds slowed the corrosion of rebars acting as an adsorption-type inhibitor. Organic compounds developed hydrophobic surfaces on concrete. Such an observation implies that salt solution may be prevented from penetrating the microcracks in concrete. Appendix I contains "Visualization of Chloride Distribution in Concrete," an abridgment submitted to the Transportation Research Board 70th Annual Meeting (1991). Appendix II contains "Rebar Corrosion under Simulated Concrete Conditions Using Galvanic Current Measurements," a paper submitted to the Transportation Research Board 70th Annual Meeting (1991).
Traffic Management Strategies for Freeway Corridors Phase II: 2nd Extension (Continuous Enhancements of the KRONOS Program)
(1991-06) Kwon, Eil; Michalopoulos, Panos; Plum, Roger
The University of Minnesota has been developing a microcomputer-based freeway simulation program, KRONOS, under a contract with Mn/DOT for the project entitled "Traffic Management Strategies for Freeway Corridors", which was scheduled to end March 31, 1990. While the prototype version of the program had been completed and proven to have the most appropriate features that Mn/DOT needed, there still remained several problems to be resolved before it could become operational. These included detailed field testing and adjustments of the program with real freeway data, analysis of sensitivities in simulation models with respect to the variations in input data, and enhancements of the input/output module to be suitable for the Mn/DOT planning environment. The main purpose of this extended project is to make KRONOS operational by resolving the above problems. In addition, a new simulation module to treat merging/diverging of two freeways is developed and incorporated into KRONOS in this project.
A Guide to Transportation Modeling Using TRANPLAN for Computer Simulation of Strategies for Managing the Rural Road Infrastructure
(1991-06) Halbach, Walter; Fruin, Jerry
The objective of this paper is to provide a starting point for those interested in using transportation modeling software in a rural road setting. An example problem will be offered, and the package that it will be demonstrated in is TRANPLAN Version 6.20 ( The Urban Analysis Group, Danville CA ). It is assumed that the reader has a basic previous understanding of microcomputer hardware, software and operating systems. With this purpose in mind, this paper will also provide example code from TRANPLAN to illustrate various parts of the analysis process. Essentially this paper is a companion guide to the various sections of the TRANPLAN manual. Because of the applied nature of this task, only cursory discussion will be expended on the development of theory. References to several articles will be made instead. The information given herein is supplied with the understanding that no discrimination is intended and no endorsement is implied. Reference to a trade or company name is for specific information only and does not imply approval or recommendation of the company or the product by the researchers, their institutions, or the granting agencies, to the exclusion of others that may be suitable for a specific product application.
Techniques for Rural Transit Service Design
(1991-08) Stephanedes, Yorgos J.; Vairamidis, Nikos
Transit service is playing an increasingly vital role in maintaining and improving the mobility and economic well-being of rural populations in the North Central region. This has been particularly important as the decline in several small towns has led to a dependency on regional centers or metropolitan areas for services formerly provided locally. While rural transit systems have become more important, higher operating expenses and reduced federal subsidies have made state transit management, design and funding decisions more complex. This project has developed methods and tools to aid these important decisions.

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