bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Water/Cement Ratio on the Early Age Tensile Strength of Concrete
Authors: Abel Jon , Hover Ken
Published: April 2007

Following Hannant’s research in the United Kingdom, the authors measured the tensile strength of concrete between the ages of 2 and 8 hr after batching. Water/cement ratios varied from 0.3 to 0.7, and water content varied from 198.6 to 220 kg/m3 (327 to 377 lb/yd3). It appears that there is a dormant period from 2 to about 4 hr when tensile strength was immeasurably low. Pragmatically this corresponds to the time period when plastic shrinkage cracking is frequently initiated. Tensile capacity developed very rapidly after the dormant period, and in all cases development of tensile strength was more rapid the lower the water/cement ratio.
Ultrathin Whitetopping: State-of-the-Practice for Thin Concrete Overlays of Asphalt
Authors: Mack James W. , Hawbaker Lon D. , Cole Lawrence W.
Published: April 2007

Ultrathin whitetopping (UTW) is a concrete overlay of a distressed asphalt pavement, 50 to 100 mm thick, with close joint spacing. The overlay is specifically bonded to the existing asphalt pavement. It may or may not contain fibers. By bonding the UTW to the existing asphalt surface, the UTW forms a composite pavement section with the underlying asphalt, which reduces the stresses in the concrete layer. This composite pavement section delivers the longer life and durable performance characteristics of concrete pavement and is cost competitive with ordinary asphalt. Many areas are discussed, but not all questions about UTW are answered. A snapshot of the current state of the practice as it now stands is presented.
Stabilization of Sulfate-Contaminated Crushed Concrete Base with Type V Cement and Fly Ash
Authors: Sarkar Shondeep L. , Little Dallas N.
Published: April 2007

The sulfate-contaminated crushed concrete base of a parking lot began to experience severe heaving because of the formation of secondary, expansive minerals (ettringite and thaumasite). Tests were performed in the laboratory to study the possibility of limiting the mobility of soluble sulfate ions by adding either a sulfate-resistant (Type V) cement or a combination of Type V cement and fly ash. The use of cement did not only prove practical because of the high moisture content of the base, but a mixture of 10 percent Type V cement and 9 percent Class C fly ash by weight yielded promising results for drying and encapsulating the free sulfate ions and providing a reasonably strong base.
Forensic Evaluation of Three Failed Cement-Treated Base Pavements
Authors: Scullion Tom , Harris Pat
Published: April 2007

Three cement-treated base (CTB) pavements constructed around 1990 near Houston, Texas, showed severe pavement deterioration after 3 to 4 years. The unusual distress patterns included wheelpath alligator cracking and severe pumping. A forensic investigation was initiated to determine the cause and to recommend modifications to materials specification, design, and construction practices to avoid future problems. The primary cause was determined to be chemical deterioration that resulted in destruction of the cement matrix. In all cases water was trapped within the CTB layer. In two bases moisture flowed rapidly by capillary action through the CTB; these bases showed the most rapid deterioration. Water flow in one case was attributed to smectite clay contamination of the fine aggregate and in another to a highly absorptive sandstone coarse aggregate. Extensive ettringite was found in one material. In one case deterioration was caused by the growth of two phases exhibiting different morphologies: hydrated calcium aluminum silicate with a radiating needle morphology and ettringite, which showed a bladed morphology in these samples. Practical recommendations to prevent recurrence of the problem were ( a) moisture absorption as acceptance testing for coarse aggregate and ( b) elimination of designs placing different stabilized materials on top of one another. The laboratory suction test that was developed is recommended as a screening test for molded CTB specimens.
Stabilization of Weak Clay with Strong Sand and Geogrid at Sand-Clay Interface
Authors: Das Braja M. , Khing Kim H. , Shin Eun C.
Published: April 2007

The load-bearing capacity of a weak clay subgrade can be increased by placing a strong granular base course of limited thickness on top of the clay layer. The load-bearing capacity can be increased further, or the thickness of the granular base course can be reduced, by separating both layers by a geogrid. Laboratory model test results for the ultimate bearing capacity of a rigid strip loading on the surface of a granular soil underlain by a soft clay with a layer of geogrid at the interface of the two soils are presented. The optimum thickness of the granular soil layer and the critical width of the geogrid layer required to derive the maximum benefit from the reinforcement were determined. Model test results on the permanent settlement of the rigid strip load caused by cyclic loading of low frequency are presented.
Speeds of Cars on Horizontal Curves
Authors: Andjus Vojo , Maletin Mihailo
Published: April 2007

Revision of existing Yugoslav road-design standards, specifically in the area of road-design speed definition, required studying driver behavior in free-flow conditions in order to define drivers’ responses to the radii of horizontal curves. A specific approach with variable design speed for horizontal curves is discussed and is supported by speed measurements on roads. The pilot research was undertaken on several test sites on Yugoslav two-lane rural roads to collect reliable speed data related to characteristics of horizontal curves. Characteristics of test sites, experimental procedures, data collected, and results of data analyses are described. It is concluded that speeds of free-flow passenger cars show good correlation with radii and that actual design policy with a constant design speed underestimates speeds in radii less than 250 m. Thus, the variable design speed concept is a more realistic approach. Further research on more test sites is recommended.
Operational Aspects of the Michigan Urban Diamond Interchange
Authors: Dorothy Paul W. , Maleck Thomas L. , Miller Kristy K.
Published: April 2007

As the Interstate highway system was constructed, a large number of freeway interchanges were designed and constructed. The design standards for these freeway interchanges, however, were not derived from an indepth analysis of past experience, because there was very little experience from which the design engineer could draw. Instead, most designs were replications and modifications of existing freeway interchanges. Thus, many of these early interchanges precede the Interstate system and Interstate standards. The simplest and perhaps most common interchange used is the urban diamond. Unfortunately, this configuration has relatively low capacity because all the turning movements occur at the intersections and left-turning vehicles have to yield to oncoming traffic. The Michigan Department of Transportation (MDOT), borrowing from its indirect left-turn strategy implemented for most at-grade urban boulevards, modified the traditional urban diamond in an effort to increase the design’s capacity. This modified diamond-interchange configuration is referred to as the Michigan urban diamond interchange (MUDI). Michigan State University and MDOT are jointly evaluating the merits of a MUDI geometric configuration. Computer modeling with TRAF-NETSIM was used to operationally compare the diamond to the MUDI. The TRAF-NETSIM simulations run on each type of interchange give valuable insight into which design is better under different volume and percent turning conditions. Operationally, the MUDI was superior to the diamond interchange in most cases. Additionally, the MUDI configuration does not transfer delay to downstream nodes, whereas the diamond interchange with frontage roads appears to affect the operation of these nodes.
Study of Long Combination Vehicles on Two-Lane Highways
Authors: Barton Raymond A. , Morrall John
Published: April 2007

In 1988, the Council of Ministers of Transportation and Highway Safety in Canada endorsed a memorandum of understanding designed to improve uniformity between provinces and territories. The regulations covering weights and dimensions for tractor-semitrailers and double combination trucks specified a maximum length of 23 m. However, in western Canada, which includes the provinces of British Columbia, Alberta, Saskatchewan, and Manitoba, a maximum vehicle length of 25 m was adopted. Vehicles longer than 25 m are generally referred to as long combination vehicles (LCVs) and include the following vehicles: triple trailer combinations, 35 m in length; Rocky Mountain doubles, 30 m in length; log haul trucks, which can be up to 30.5 m in length; and turnpike doubles, 38 m in length. A study was conducted to develop recommendations relating to the use of LCVs on two-lane highways in Alberta. The basic approach was to examine the incremental impact of LCV-type vehicles on two-lane highway operations compared with a baseline vehicle type, namely, 25-m standard double heavy trucks. Although the study of LCVs examined a range of issues that included low- and high-speed offtracking, and aerodynamic buffeting, only the findings related to traffic volume criteria are presented. The main recommendation with respect to passing opportunities and level of service was the development of maximum traffic volumes for two-lane highways with and without passing lanes and with a given percentage of passing zones. The main criteria are to ensure that a net passing opportunity of at least 30 percent is provided to drivers impeded by LCVs. This is roughly comparable to providing to Level of Service C. For example, the maximum volume below which Rocky Mountain doubles may operate on a two-lane highway is 425 veh/h for a section with 100 percent passing zones. If 2-km passing lanes are provided every 10 km, Rocky Mountain doubles could operate at traffic volumes up to 734 veh/h and still ensure a net passing opportunity of 30 percent.
Main Freight Land Transport Corridors in Mexico
Authors: Rico Alfonso , Mendoza Alberto , Mayoral Emilio
Published: April 2007

The current modal share between highway and railroad in freight land transportation in Mexico is presented. Based on available origin and destination (O-D) data, the most important origin and destination points of freight transportation by both modes are identified. Information is also provided on the multicommodity flows taking place in Mexico. The O-D information and network assignment analyses are used to establish the major Mexican land transport corridors and their characteristics. The possible extension of these corridors to the U.S. road and railroad corridors that are more important for the binational trade is indicated. Data about the recent evolution of this trade are presented. Only freight transportation is discussed.
Potential Effects of Advanced Technologies at Commercial Border Crossings
Authors: Nozick Linda K. , List George F. , Turnquist Mark A. , Wu Tzu-Li
Published: April 2007

Between 1991 and 1995, trade between the United States and Canada increased 55 percent, and trade between the United States and Mexico grew 68 percent. This growth in traffic has strained the available capacity and has led to frequent delays as vehicles pass through congested border-crossing facilities. Delays at the border may be reduced through the use of information technologies. A generic simulation model was developed of a border crossing that can be used to evaluate the benefit of information technologies to speed the processing of commercial vehicles at the border. This model is tested with input data that are reflective of the Peace Bridge, which links Buffalo, New York, with Fort Erie, Ontario, to develop general relationships between the penetration rate of advanced technology in the commercial vehicle traffic and the benefits to be achieved. This analysis indicates that the effective use of information technologies can significantly improve the services offered and reduce the amount of resources needed.
Multiobjective Routing and Scheduling of Hazardous Materials Shipments
Authors: Sulijoadikusumo G. , Nozick L.
Published: April 2007

Good routing and scheduling decisions for hazardous materials shipments often require the explicit consideration of multiple objectives. Also, the performance of the relevant facilities in the transportation system typically varies by time of day with respect to many of these objectives. The authors discuss the reliability and performance of a heuristic that can be used to identify good routes and schedules for hazardous material shipments. Presented is the second part of a two-part analysis. The first part described a method for performing an integrated routing/ scheduling analysis with multiple objectives when the arc attributes are time variant. This part discusses the quality of that analysis and additional heuristics that can be used to improve the quality of the solution generated.
Oil Spill Response Systems of South Florida and the Country of Qatar
Authors: Najafi Fazil T. , McKenzie Roy
Published: April 2007

Both South Florida and Qatar have unique needs and requirements for oil spill response, yet both have basic needs for a contingency plan for responding to oil spills. South Florida has a diverse coastal environment that is important not only for its ecosystem but for the revenue it generates from tourism and fishing. Qatar is sitting on the world’s largest natural gas fields and some larger oil fields and is one of the world’s richest countries. The oil spill response system of South Florida differs in operational structure from that of Qatar. South Florida’s response system is a network-based operation controlled by county or city officials, depending on the degree of the spill and availability of resources. Qatar’s system is a central control operation, with primary authority and control of any oil spill response assumed by the Qatar General Petroleum Corporation (QGPC). Local industries are expected to protect their own facilities, but QGPC also responds to those spills that threaten public and government coasts and the Persian Gulf ecosystem. The University of Florida has developed a computerized database for South Florida that enables officials of national, regional, and state response teams to quickly identify and deploy required equipment and personnel for an oil spill and to follow cleanup operations. The specific advantage of the South Florida system over the Qatar system is in the oil spill response information system database, which includes information on oil-sensitive shorelines, response teams, disposal sites, cleanup organizations, and equipment. Furthermore, the typical oil spill cleanup response times for selected contractors indicate the most efficient choice of contractor for possible oil spills at different locations.
Calibration of a Miniature Cone Penetrometer for Highway Applications
Authors: Kurup Pradeep U. , Tumay Mehmet T.
Published: April 2007

The electronic cone penetrometer is an important in situ investigation tool of choice for site characterization. Application of this proven concept of the cone penetration test (CPT) to highway design and construction control by miniaturization is described. A miniature cone penetrometer with a projected cone area of 2 cm2 has been developed and implemented in a continuous intrusion miniature cone penetration test system (CIMCPT). This device may be used for rapid, accurate, and economical characterization of sites and to determine engineering soil parameters needed in the design of pavements, embankments, and earth structures. The miniature cone penetration test (MCPT) gives finer details than the standard 10-cm2 cross-sectional area reference cone penetrometer. This makes the MCPT attractive for subgrade characterization, quality-control assessment, compaction control of embankments, and assessment of ground improvement effectiveness for transportation infrastructure. In situ calibration of the CIMCPT system was conducted at a highway embankment site in Baton Rouge, Louisiana. MCPT penetration profiles were compared with those obtained by using the standard cone penetrometer at the same site. The tip resistance of the MCPT was 10 percent higher than that of the reference CPT. The sleeve friction and friction ratio of the reference CPT were higher than that of the MCPT by 12 and 23 percent, respectively. Calibration was also performed to determine empirical cone factors required for estimating undrained shear strength from MCPT data.
Springtime Thaw Weakening and Load Restrictions in Minnesota
Authors: Van Deusen Dave , Schrader Craig , Bullock Dave , Worel Ben
Published: April 2007

In regions of the United States where pavements are constructed in freeze-thaw environments, springtime load restrictions are used to reduce distress caused by truck loads. During the spring, the pavement layers can be saturated and weakened because of partial thaw conditions and trapped water. Knowledge of the timing of freeze-thaw events is crucial to a successful load restriction strategy. Several studies in Minnesota are being done to evaluate criteria used to predict when to place and remove springtime load restrictions. The objectives are to evaluate current load restriction procedures, investigate pavement strength changes in relation to freeze-thaw events, and suggest improvements to current procedures. Data collected from eight Minnesota Road Research Project (Mn/ROAD) flexible pavement test sections, including falling weight deflectometer, response, and environmental data, were used to assess the effects on pavement strength. In conjunction with the Mn/ROAD work, the Minnesota Department of Transportation is conducting a statewide study using resistivity probes to monitor frost depth beneath various roads around the state. It was found that the existing procedure works well in predicting the thaw if the warming trend is uniform. In addition, over the past four springs the predicted thaw duration was greater than field observations. The date of maximum deflection occurs about 1 to 3 weeks after thawing is complete; the rate of strength recovery is quicker in sections constructed on higher quality base materials with low fines content. On the basis of the results a new criteria and equation for predicting the beginning and duration of the thaw are proposed.
Field Assessment of Changes in Pavement Moduli Caused by Freezing and Thawing
Authors: Jong Da-Tong , Bosscher Peter J. , Benson Craig H.
Published: April 2007

Three secondary highways with flexible pavements were instrumented for 18 months to monitor changes in pavement moduli caused by seasonal meteorological changes. Temperatures, water contents, and water phase changes in the subsurface as well as meteorological conditions were recorded every 2 hours throughout the study. Pavement moduli were regularly determined by conducting surveys with a falling weight deflectometer and by performing backcalculations using the program Modulus. The moduli of the base and subgrade typically increased 12 to 4 times, respectively, when frost penetrated the subsurface. When the base and subgrade began to thaw, the moduli decreased substantially. The base moduli decreased the most, typically being about 35 percent of the prefreezing values by the end of thaw. Smaller decreases occurred in the subgrade. The subgrade moduli were about 65 percent of their prefreezing values by the end of thaw. The moduli continued to decrease until thaw was complete and then gradually recovered back to the original prefreezing values. Complete recovery required approximately 4 months. Similar changes in moduli were observed regardless of site or year.
Image Analysis Evaluation of Aggregates for Asphalt Concrete Mixtures
Authors: Kuo Chun-Yi , Freeman Reed B.
Published: April 2007

The performance of asphalt concrete mixtures is influenced by the properties of the included aggregates, such as grading, shape (angularity and elongation), and texture (roughness). Complete and accurate quantification of aggregate properties is essential for understanding their influence on asphalt concrete and for selecting aggregates to produce high-quality paving mixtures. Recent developments in the use of digital image analysis techniques for quantifying aggregate morphological characteristics in asphalt concrete are summarized. Image morphological characteristics were used to quantify flatness and elongation of coarse aggregates, to estimate the proportion of natural sand in fine aggregates, and to correlate aggregate characteristics with engineering properties of asphalt concrete mixtures. Image analysis of sections also revealed information about the grading, shape, and orientation of coarse aggregates in a mixture. An overview is presented of the broad range of useful pavement engineering applications of this relatively new approach for evaluating aggregate characteristics.
Georgia Department of Transportation's Progress in Open-Graded Friction Course Development
Authors: Watson Donald , Johnson Andrew , Jared David
Published: April 2007

To improve the safety of motorists on Georgia highways, the Georgia Department of Transportation (GDOT) has continued to use the most advanced and effective pavements available, including the open-graded friction course (OGFC). Since OGFCs were conceived in the 1950s and 1960s, GDOT has used these mixes as thin porous wearing layers primarily on Interstate highways. In the past, GDOT encountered problems with OGFC use, including asphalt cement (AC) draindown, rapid oxidation, raveling, and stripping of underlying layers. Consequently, GDOT placed a moratorium on OGFC use in 1982. Since that time, however, several modifications have been made to improve the performance of OGFC mixes. Hydrated lime is added as an antistripping agent to OGFC and to all other mixes used on the Georgia state route system, including dense-graded mixes that underlie OGFC. Fibers are added to eliminate AC draindown. Polymer-modified AC is added to improve the durability of the pavement by reducing problems associated with premature oxidation and raveling. Production temperatures are increased to more thoroughly dry aggregate components and thus improve AC adhesion. Finally, coarser gradations and thicker layers are used to improve permeability. With the modifications made to these mixes in the last few years, significant improvements in mix performance have already been noted. Agencies that have used this mix in the past and experienced problems similar to those experienced by GDOT should consider using this modified OGFC on high-volume traffic facilities.
Moving Toward Sustainability: Transforming a Comprehensive Land Use and Transportation Plan
Authors: Lindquist Eric
Published: April 2007

Sustainability and sustainable development have been, perhaps, the most debated yet least applied concepts in urban and regional planning in recent years. Missing in all the rhetoric on and research into sustainable development are guidelines for moving toward plans that, either incrementally or comprehensively, incorporate sustainable objectives and the steps necessary to implement them. An approach is outlined for developing measures and steps to transform a traditional community-based comprehensive land use and transportation plan into one incorporating sustainable development objectives and measures. Traditional objectives of comprehensive land use and transportation planning are identified and linked to their sustainability equivalents. Four elements are discussed: land use, transportation, environmental factors, and economic development. A four-step, dynamic process is described for implementing the model and transforming the plan objectives, its implementation, and its measures of success. A tool for strategically assessing the political climate for change is included to assist planners in identifying an acceptable scale of movement toward sustainability. In conclusion, the elements presented provide a strategy and tools for moving forward in adopting sustainability as a local objective for land use and transportation planning.
Measuring the Impact of Light Rail Systems on Single-Family Home Values: A Hedonic Approach with Geographic Information System Application
Authors: Chen Hong , Rufolo Anthony , Dueker Kenneth J.
Published: April 2007

In theory, proximity to light rail transit (LRT) may have two different effects on residential property values. On the one hand, accessibility (proximity to LRT stations) may increase property values. On the other hand, nuisance effects (proximity to the LRT line and stations) may decrease property values. Existing empirical studies are inconclusive, and failure to separate the effects of accessibility from the nuisance effects may explain some of the ambiguity. An examination is presented of the impact of the light rail system (MAX) in Portland, Oregon, on single-family home values using distance to rail stations as a proxy for accessibility and distance to the line itself as a proxy for nuisance effects. Geographic information system techniques are employed to create spatial-related variables and merge data from various sources. The study results confirm the hypothesis that the light rail has both a positive effect (accessibility effect) and a negative effect (nuisance effect) on single-family home values. The positive effect dominates the negative effect, which implies a declining price gradient as one moves away from LRT stations for several hundred meters. Without controlling for the nuisance effect of the distance to the rail line, the estimated coefficients on distance from stations appear to be biased and would underestimate the accessibility effect. The finding of an independent nuisance effect suggests that previous hedonic models may have reached contradictory results because the nuisance effect differs with different types of rail or other local characteristics.
Presentation of Comparative Data for Transportation Planning Studies
Authors: Guyton Joseph W.
Published: April 2007

Clear, yet detailed, presentations of transportation planning data to lay groups as well as to technical groups is becoming more and more of a necessity in the planning process. The transportation professional is faced with the challenge of presenting technical analyses in a manner permitting others to make their own, sound, choices. Increasingly, the choice of a preferred alternative involves both technical aspects and seemingly intangibles or quality aspects. Technical analyses often appear to press in one direction, whereas other considerations give a different perspective on the preferred solution. Peer groups as well as administrators of programs are faced with the need to quickly understand complex planning relationships. Presentation of technical information in understandable terms has become increasingly critical to the decision-making process. Professionals develop significant quantitative data to compare and contrast alternatives under investigation, and there is a need to render the results comprehensible for those making recommendations and those making decisions. The application of simple but effective comparison techniques designed to provide high flexibility to individuals in comparing alternatives is addressed. The screening techniques used in recent studies for ISTEA high-priority corridors and feasibility studies are explored and how a matrix analysis technique has applications in many studies is illustrated.
Planning Lee County’s Variable-Pricing Program
Authors: Burris Mark , Swenson Chris
Published: April 2007

Congestion (or variable) pricing can be described as the charging of more for goods or services during periods of peak demand. In theory, this practice would prove beneficial as a travel demand management tool when setting fares on toll roads and bridges. However, in practice, it has proven extremely difficult to implement in the United States. Many of the planning issues and solutions found during the early phases of a variablepricing pilot study currently being conducted in Lee County, Florida, are examined. Also examined is the electronic toll collection system being implemented in conjunction with variable pricing. The planned variablepricing scheme is detailed, along with how this publicly and politically palatable pricing scheme was derived. Data collection efforts, which include origin-destination surveys, focus groups, mail-back surveys, videotaping of traffic, and detailed traffic counts are described to emphasize the substantial effort undertaken to obtain accurate and meaningful variable-pricing traffic behavioral data that can be applied across the country. A summary of work to date and an overview of the next steps toward implementation of the variable-pricing program in Lee County are presented.
Evaluation of Accessibility of Urban Transportation Networks
Authors: Sathisan Shashi K. , Srinivasan Nanda
Published: April 2007

A framework is presented for evaluating the accessibility of urban networks to the transportation needs in urban areas. Accessibility has been defined from the point of view of the network configuration and its relationship to key factors influencing travel demand. The definition is a departure from the traditional methods of accessibility, which primarily describe the interaction of people and places. The definition in this study helps in assessing the interaction between the trip maker and the transportation network, thus helping in an evaluation of the utility of the network to trips in a study region. The methodology uses the computational capabilities of a geographic information system and relates them to the traditional urban transportation planning process. Specific indexes are presented to quantify the accessibility of the network with respect to key factors influencing trip production and attraction. The methodology presented is applicable to the analysis of accessibility of other transportation system networks and to comparisons of the accessibilities of networks of different urban areas.
Multiperiod Highway Improvement and Construction Scheduling: Model Development and Application
Authors: Eldessouki Wael , Rouphail Nagui , Beja Madalena , Ranji Ranjithan S.
Published: April 2007

A methodology is presented that emulates the transportation improvement planning process using mathematical optimization techniques. The scheduling problem is formulated as a mixed integer linear program (MILP) and can be considered as a multiperiod network design problem. The three primary model components are discussed: ( a) the input module in which the network, traffic demand, and pool of potential projects are identified over the planning horizon; ( b) the benefits estimation module using network travel time as the benefit criterion; and ( c) the schedule builder, an MILP that attempts to maximize the total benefits subject to annual resources and project precedence constraints. The proposed method is applied in a case-study context to the Lisbon metropolitan region’s network, a portion of Portugal’s highway network, and the results are discussed.
Making the Connection: The Transportation Improvement Program and the Long-Range Plan
Authors: Younger Kristina , O’Neill Christopher
Published: April 2007

The Capital District Transportation Committee (CDTC), the metropolitan planning organization for the Albany, New York, area, provides an illustration of a number of effective connections between the long-range plan and the federal-aid capital program. CDTC took over 3 years to develop a performance-based, stakeholder-driven, long-range transportation plan, called New Visions. New Visions goals, programming principles, and budget targets guided the development of the transportation improvement program for flexible federal aid in the region. The Intermodal Surface Transportation Efficiency Act’s (ISTEA’s) fiscal constraint requirements were used to broaden the horizons and perspectives of potential fund sources, as well as to focus on the strategic use of the federal-aid program to meet long-range goals. Using a combination of innovative techniques and the “tried-and-true” foundation of the benefit-cost analysis, a capital program was built in a stepwise fashion, beginning with a policy decision to honor existing commitments prior to considering new projects. The methods and process used show how a medium-sized metropolitan planning organization effectively leveraged the metropolitan planning provisions of ISTEA to advance a positive agenda for the region.
Mon/Fayette Route 51 to Pittsburgh Transportation Project: A Success Story in Integrating Congestion Management System Analysis, Major Investment Study, and National Environmental Policy Act Processes
Authors: Shalkowski Joseph S.
Published: April 2007

The 1991 Intermodal Surface Transportation Efficiency Act placed new emphasis on transportation planning. In response, FHWA and FTA issued Joint Statewide and Metropolitan Planning Regulations (23 C.F.R §450). These regulations call for two studies, the congestion management system (CMS) analysis and the major investment study (MIS), which must be completed to analyze the best use of the existing transportation network and to determine whether and what transportation investments are needed in a metropolitan area. The intent is to use these studies as input to the metropolitan planning organization’s long-range transportation plan. The Pennsylvania Turnpike Commission (PTC) and the Southwestern Pennsylvania Regional Planning Commission (SPRPC) cooperatively developed and implemented an effective approach to navigate the Mon/Fayette Route 51 to Pittsburgh transportation project through a collaborative process integrating the CMS analysis and MIS. This approach also met the requirements of the Pennsylvania Department of Transportation’s (PennDOT’s) Preliminary Alternatives Analysis, one in a series of studies required under PennDOT’s National Environmental Policy Act (NEPA) implementing guidelines. PTC’s goal to advance a preferred major investment alternative into the next phase of project development was accomplished when SPRPC endorsed the integrated CMS analysis/MIS and preliminary alternatives analysis report. Presented is a success story in the effort to integrate the metropolitan planning and NEPA processes at the project programming level. It is hoped that the planning and NEPA principles applied can serve as a model to advance other transportation projects.
Innovative Approach to Multiple-Criteria Evaluation of Multimodal Alternatives: Newberg-Dundee Transportation Improvement Project Case Study
Authors: Schwartz Marcy , Merkhofer Miley (Lee) , Upton Richard
Published: April 2007

Dissatisfied with the time and resources required to conduct a number of high-profile, controversial major investment studies, the Oregon Department of Transportation (ODOT) decided to use the Newberg-Dundee transportation improvement project to explore methods for streamlining the alternatives analysis process and better controlling the time frames and expenditures for these efforts. The Newberg-Dundee project concerned a highly congested segment of highway just outside the Portland metropolitan area. Over 95 percent of all trips in the corridor are made by automobile; public transportation in the area is infrequent and ineffective. Heightening the area’s transit needs is a population growth rate substantially higher than the statewide average. Previous studies had not incorporated a comprehensive evaluation of modal alternatives. The Newberg-Dundee alternatives analysis was completed in 9 months on a budget significantly lower than budgets for comparable previous studies. Within ODOT, the approach may serve as a model for early integration of environmental and planning activities in alternatives analyses for project development. Explored are innovative aspects of the six-step decision process used in this major investment analysis, which led to a selection of alternatives to be forwarded for detailed evaluation in an environmental impact statement. The paper focuses on management structure, definition of multimodal alternatives, development and application of a quantitative, multiple-criteria evaluation framework, and strategy for compliance with National Environmental Policy Act requirements.
Forecasting Multiple-Period Freeway Link Travel Times Using Modular Neural Networks
Authors: Park Dongjoo , Rilett Laurence R.
Published: April 2007

With the advent of route guidance systems (RGS), the prediction of short-term link travel times has become increasingly important. For RGS to be successful, the calculated routes should be based on not only historical and real-time link travel time information but also anticipatory link travel time information. An examination is conducted on how realtime information gathered as part of intelligent transportation systems can be used to predict link travel times for one through five time periods (of 5 minutes’ duration). The methodology developed consists of two steps. First, the historical link travel times are classified based on an unsupervised clustering technique. Second, an individual or modular artificial neural network (ANN) is calibrated for each class, and each modular ANN is then used to predict link travel times. Actual link travel times from Houston, Texas, collected as part of the automatic vehicle identification system of the Houston Transtar system were used as a test bed. It was found that the modular ANN outperformed a conventional singular ANN. The results of the best modular ANN were compared with existing link travel time techniques, including a Kalman filtering model, an exponential smoothing model, a historical profile, and a real-time profile, and it was found that the modular ANN gave the best overall results.
Game-Theoretic Formulations of Interaction Between Dynamic Traffic Control and Dynamic Traffic Assignment
Authors: Chen Owen , Ben-Akiva Moshe
Published: April 2007

The dynamic traffic control problem and the dynamic traffic assignment problem are integrated as a noncooperative game between a traffic authority and highway users. The objective of the combined control-assignment problem is to find a mutually consistent dynamic system-optimal signal setting and dynamic user-optimal traffic flow. The combined control-assignment problem is first formulated as a one-level Cournot game: the traffic authority and the users choose their strategies simultaneously. The combined control-assignment problem is subsequently formulated as a bi-level Stackelberg game. The traffic authority is the leader; it determines the signal settings in anticipation of the users’ reactions. The users are followers who choose their routes after the signal settings have been determined. Finally, the system-optimal control-assignment problem is formulated as a Monopoly game. The sole player—the traffic authority—determines both signal settings and traffic flows to achieve a dynamic system-optimal solution. A numerical example is provided to illustrate the equilibria of the games.
Transportation Management Plan Update
Authors: Hansen Matt , Liljeblad Kris , Yoshida Cheryl
Published: April 2007

In January 1997 the Bellevue, Washington, office of CH2M HILL, a full service engineering consulting firm, implemented a new transportation management plan (TMP), replacing an innovative TMP implemented in 1987 that had gained attention nationwide. The results were remarkable: drive-alone commuting by CH2M HILL employees dropped from 61 to 40 percent in just a few months’ time. An employee-led committee adopted the new TMP before an increase in parking fees, a condition of the company’s building lease. The committee desired to offer employees an alternative to higher parking fees. The new TMP included King County Metro’s transportation benefits package called the FlexPass, along with a host of other incentives. The combination of higher parking fees and very inexpensive access to transit and vanpools led to a successful update to an already effective program. It is important to note that the tools were largely in place to support the mode shift: The CH2M HILL office is located within a city block of the downtown Bellevue transit center; an extensive park-and-ride system supports the transit center; the building is equipped with bike racks, showers, and lockers and is served by a transportation management organization; and the company has corporate vehicles available for work-related trips. Since these favorable conditions were already in place, the combination of the transit incentive and parking cost increase changed employees’ commuting habits.
Individualized Marketing: Implications for Transportation Demand Management
Authors: Brög Werner
Published: April 2007

Recently an international demonstration project was carried out between SOCIALDATA and the International Association of Public Transport to create awareness of an innovative marketing approach to increasing public transport use called “individualized marketing.” SOCIALDATA undertook a series of experimental projects designed to prove the effectiveness of subjective perceptions, the so-called “soft policies.” The starting point was the recognition that use of public transport is hindered by a lack of experience and motivation to use it. Potential users of public transport were contacted directly with the intent of motivating them to think about their behavior. Then the test groups were thoroughly informed about public transport and selected test candidates were given a (transferable) ticket to use public transport free of charge for one full month. The experiment was extremely successful: use of public transport for the test group nearly doubled. Next a method was developed allowing the management of projects on the scale of several thousand households. The concept was applied in numerous projects, which all showed the positive results of individualized marketing: a significant increase in the use of public transport. Surplus revenue was available to finance the innovative marketing approach, which has led to a measurable image improvement for public transport and its companies. Therefore, individualized marketing has proved to be a quick, cost-effective method to increase areawide public transport patronage.
Issues in Fare Policy: Case of the New York Taxi Industry
Authors: Schaller Bruce
Published: April 2007

Setting taxi fares is one of the most delicate and difficult tasks faced by taxi regulators. Fare setting is delicate because political forces are strong on both sides of the issue. The difficulties lie in reliably determining taxi costs and revenues and how a fare increase will affect service quality. Major issues commonly raised in connection with fare policy are considered, including the goals of fare changes, the relevance of medallion prices, and implications for service availability. It is concluded that fare increases can achieve their goal of increasing revenues to the taxi industry but that additional regulatory action is required to ensure improvements to driver and vehicle quality. Arguments that fare increases are unnecessary in the face of high medallion prices are shown to be impractical and possibly counterproductive. Finally, it is argued that fare increases expand the availability of taxi service and that availability considerations should be an integral part of fare policy.
System Selection, Benefits, and Financial Feasibility of Implementing an Advanced Public Transportation System
Authors: Ohene Fred A. , Kaseko Mohamed S.
Published: April 2007

A procedure for selecting a suitable backbone radio communications system necessary for the implementation of advanced public transportation system technologies is presented. This procedure was used by the Regional Transportation Commission of Clark County, Nevada, in preparation of a radio communications master plan for the Las Vegas Citizens Area Transit system. The procedure recognizes the importance of taking into account not only the relative costs of the alternative candidate systems, but also other important factors such as the degree of system control by the transit agency, confidence in system development and technical practicality, potential for future expansion, and technical simplicity. Several alternative technologies for radio communications are reviewed and evaluated. Selection of the recommended system is based on the procedure that assigns relative weights to the important factors and gives each candidate system a score for each factor. The system with the highest total score is recommended for implementation. Potential system benefits are discussed and financial feasibility of the recommended system is evaluated by computing the annual rate of return on invested capital. Analysis shows that the system can pay for itself and also produce significant net savings in operation and capital costs. Although the analysis considered only potential savings in fleet size, an annual rate of return of over 21 percent on the invested capital has been shown to be achievable. Such savings can enable transit agencies to provide the same level of service at significantly reduced cost or expand the service without increasing operating costs.
Transit Time Internet Access
Authors: Vorvick Janet , Dueker Kenneth J.
Published: April 2007

Transit Time Internet Access (TTIA) is a World Wide Web application that delivers real-time bus schedule information to users of the Internet. TTIA allows a bus rider to request and receive schedule deviation information about a specific bus at a specific time. The design of TTIA, the specifics of the implementation, the issues of scope, and the problems that were encountered are described, and some conclusions are drawn. TTIA is accessible at .
Integrated Service Planning in Dordrecht
Authors: Cheung Francis
Published: April 2007

In the Netherlands, public transport planning plays an important role in strategic planning. The Dutch government is pursuing policy changes to ensure sustainable development. The objectives are to raise transit’s share in the modal split and to improve operators’ financial performance. Dordrecht Municipal Authority has taken an integrated approach to public transport planning to complement its urban development strategy. In June 1997 the three-bus system was introduced with the objectives to stimulate ridership and increase revenue: the express bus provides direct, speedy connections with high frequency to serve commuter journeys; the city bus uses liquefied petroleum gas vehicles with 3- to 10-min headways to connect the historical city center with the Central Station; and the service bus improves the connectivity of neighborhoods and enhances accessibility between the suburbs and the city center. The service net is also designed to serve the mobility needs of elderly and handicapped passengers in wheelchairs. The integrated network aims to provide quality service to meet passenger requirements. To finance the new system, an extra fare zone was introduced in January 1998. A research program in three phases has been implemented to monitor and evaluate the effects.
Securing Objective Data on the Quality of the Passenger Environment for Transit Riders: Redesign of the Passenger Environment Measurement System for the Bay Area Rapid Transit District
Authors: Weinstein Aaron , Albom Rhonda
Published: April 2007

The San Francisco Bay Area Rapid Transit District (BART) recently revised the techniques it uses to collect data on qualitative areas of performance that are difficult to measure, such as station cleanliness, train cleanliness, graffiti removal, and restroom cleanliness. This paper documents the methodological changes implemented by BART and compares the accuracy of the new and the old techniques. Empirical evidence is presented demonstrating that the new data collection methods yield more reliable and objective statistics than the old system of measurement. Findings from this study suggest that reliable measurement of qualitative areas is possible. When carefully collected, these kinds of measurements can become an important component of an organization’s overall strategy to monitor and improve service quality.