bluuebunny/crossref_metadata_2025 huggingface dataset:
Incident Detection on an Arterial Roadway
Authors: Culli Michael J. , Hall Fred L.
Published: April 2007

Presented here is the development of an automatic incident detection algorithm for use on Lakeshore Boulevard, Toronto, Canada, based on volume or occupancy data recorded from fixed-loop detectors. Four prospective logics were based on 20-sec intervals; the remaining five were based on traffic-signal cycle lengths to eliminate the fluctuations in 20-sec data. To identify the detection ability of each logic, data from a known severe incident (a two-lane blockage) were used. Only one logic exhibited promising results from the initial development and feasibility test: the logic that compared current cycle volume and occupancy values with those averaged over the previous 3-, 5-, and 10-cycle periods. Further evaluation was conducted on this logic. A data base was developed around two additional reported serious incidents; the logic detected both incidents before their official start times. A second data base, which consisted of data from 13 days, was developed to test the overall performance of this logic, focusing specifically on false alarms. On average, one unexplainable false alarm was reported for every 5 hr of data tested for the entire Lakeshore system (49 detector stations). Testing with additional Lakeshore incident data in a real-time environment is required to fully investigate the ability of this algorithm to detect serious incidents. As developed, this logic cannot distinguish between congestion due to incidents and recurrent congestion. The latter was responsible for the majority of the alarms as tested and thus future improvements should focus on this aspect.
Transit Incentive Program for Transit-Dependent Riders
Authors: McLaughlin James , Boyle Daniel K.
Published: April 2007

Five years ago, several transportation agencies in Los Angeles County began discussions on developing a process to reevaluate the existing bus service delivery system, including the opportunity for public involvement and participation. As a result, the concept of a thorough restructuring study was developed. Restructuring studies are closely related to other activities focused on the bus system. In March 1996, the Metropolitan Transportation Authority (MTA) board approved a broad-based bus system improvement plan that tied together many of the ongoing service improvements with proposed plans and programs to provide a 2- to 5-year set of goals to improve bus service in Los Angeles. It is in this context that the MTA and the Los Angeles Department of Transportation commissioned a special work effort as part of the Central/East/Northeast restructuring study to examine options for a transit incentive program for transit-dependent riders. The transitory nature of transit dependency has gained increased awareness in recent years, but development of effective strategies has lagged behind as transit agencies have targeted discretionary travelers as the largest pool of potential riders. The approach taken is to identify and describe rider-incentive programs implemented at other transit agencies that target or can be applied to the transit-dependent population, to consider public input about incentives and rewards that would be attractive to these riders, and to note key neighborhoods in the study area where there are significant numbers of households without automobiles. The objectives are to develop options for a pilot incentive program and to define the type of area appropriate for a focused demonstration-type project. The application of ideas as part of the consent decree negotiated by the Los Angeles County MTA is summarized.
Public Transport Pricing Policy: Empirical Evidence of Regional Bus Card Systems in Finland
Authors: Dargay J. , Pekkarinen S.
Published: April 2007

A research project is concerned with evaluating the effects of new integrated fare and ticket policies on bus use in Finland. The objective of the policy is to reduce energy consumption and the environmental effects of transport by encouraging a modal shift from cars to public transport. The scheme is based on introduction of a monthly regional bus card that offers a substantial discount on normal fares and that is valid from city center to smaller independent communities. The regional bus card is subsidized by local authorities and the state government. Estimates are presented of the fare elasticities of the demand for bus services in two regions in Finland—Oulu and Kuopio—where the regional bus card system has been introduced. The demand for bus cards and for travel with these cards is analyzed. The models used take into account different fare structures as well as the levels of fares, income, car-use costs, and service quality. The estimated elasticities indicate that in the medium-sized Finnish communities analyzed, the demand for both regional bus cards and trips when these cards are used are highly sensitive to price and income. The results are to be used in conjunction with other survey data for a preliminary assessment of the effect of the bus card system on bus patronage and car use.
Guidelines for Left-Turn Phasing Treatment
Authors: Stamatiadis Nikiforos , Agent Kenneth R. , Bizakis Apostolos
Published: April 2007

The safety of left-turning vehicles at signalized intersections is a concern of the safety community, and guidelines for the installation of left-turn phasing have been developed. The development of guidelines to be considered when determining whether left-turn phasing should be used and the type of phasing that would be appropriate is presented. The guidelines are based on accident data collected for 408 approaches in Kentucky and delay data simulated for a variety of intersection characteristics. The recommendations made take into account many variables, including left-turn volumes, accident rates, product of opposing and left-turn volumes, and left-turn delays. A two-step approach is considered in the decision whether to install left-turn phasing: determine whether protection is needed and then determine the type of protection. The selection of the appropriate left-turn treatment is a process in which trade-offs between safety and delays may be required. Moreover, the use of single rules is usually not adequate to determine the appropriate left-turn treatment; a variety of other factors must be considered.
Visibility of New Centerline and Edge Line Pavement Markings
Authors: Zwahlen Helmut T. , Schnell Thomas
Published: April 2007

The objective of the presented two-part study was to provide nighttime pavement-marking visibility data obtained under automobile low-beam illumination conditions in the field for further calibration of the Ohio University pavement-marking visibility model CARVE (Computer Aided Road Marking Visibility Evaluator). A total of 10 subjects participated in Part 1 of the study. The goal of Part 1 was to determine the end-detection distance of finite-length, new, medium-retroreflectivity, yellow pavement marking tape centerlines without edge lines as a function of the centerline configuration (single dashed, single solid, and double solid) and width. The results of Part 1 confirm that an increase in the average end-detection distance of about 55 percent represents the approximate upper limit of what can be achieved by adding more retro-reflective area to a yellow centerline. Part 2 consisted of four main experiments involving 10 subjects each and two follow-up experiments involving a total of 10 subjects. The goal of Part 2 was to provide pavement-marking end-detection distance data for fully marked roads consisting of left and right white edge lines with either a yellow double solid or single dashed centerline. The main effects of width, retroreflectvity, and centerline configuration were found to be statistically significant. A fully marked road consisting of both edge lines and a centerline generally appears to provide end-detection distances that are on average about twice as long as the end-detection distances that can be achieved with a centerline alone, without edge lines.
Collaborative Decision Making: Using Multiattribute Utility Analysis to Involve Stakeholders in Resolution of Controversial Transportation Issues
Authors: Schwartz Marcy , Eichhorn Constance
Published: April 2007

Instead of comparing a broad range of alternatives against common criteria, traditional transportation alternatives analysis methods tend to pit supporters of one alternative against those of another. As a result, public involvement processes intended to help resolve controversial issues often polarize the public and force decision makers to side with one position or another. However, a simple form of multiattribute utility analysis (MUA) has proved very effective in involving stakeholders in a collaborative process. This type of analysis is relatively inexpensive to execute, fosters problem solving, and has a high probability of leading to a defensible, implementable decision. This modified MUA approach has been applied to two California freeway-access projects.
Assessment of Influence of Land Use–Transportation System on Travel Behavior
Authors: McNally Michael G. , Kulkarni Anup
Published: April 2007

An empirical assessment of the interaction between the land use–transportation system and travel behavior is presented. A methodology for identifying a range of land use–transportation systems by a clustering technique with network and land use inputs was developed. Twenty neighborhoods from Orange County, California, were considered in this process. Three groups, or themes, were found to best represent the neighborhoods in the sample area: one each associated with the conventional definition of traditional and neotraditional neighborhood design (TND) and planned unit development (PUD) neighborhoods and one representing neighborhoods that blend characteristics of TND and PUD. Conventional measures of individual travel behavior were compared with an analysis of variance between the themes to identify significant differences, controlling for socioeconomic characteristics. Research results include the development of (a) a systematic methodology to identify a more explicit land use–transportation dimension, (b) an estimate of the potential effectiveness of design-oriented solutions to reduce automobile congestion by using the developed themes, and (c) a preliminary assessment of the extent to which development themes can be used to improve the current modeling framework.
Commuters’ Departure Time Decisions in Brussels, Belgium
Authors: De Palma André , Khattak Asad J. , Gupta Deepak
Published: April 2007

Factors that influence commuters’ departure time decisions are explored, especially the trade-off between travel time and schedule delay. Stated and reported behavior data obtained from a survey of commuters in Brussels, Belgium, were used to analyze the influence of socioeconomic and contextual variables. The key findings were as follows. Daily schedules for flextime and fixed-time commuters were quite similar, suggesting that flextime commuters do not extensively use their flexibility to avoid peak-period congestion. When commuters changed their departure times between home and work, their arrival times shifted by a similar amount. This implies that the shortening of travel time is not as critical as other reasons, such as requirements and personal convenience, in motivating departure time changes. Furthermore, 35 to 50 percent of the respondents were unwilling to change their departure times to save 10 min of travel time. Therefore, departure time changes may not be feasible in many cases for the range of travel times encountered in urban areas. Among those willing to make further trade-offs by changing departure times, the values for the early and late schedule delay–travel time trade-off were similar for both the stated and the reported preferences and were broadly consistent with those from other studies. The travel time–schedule delay trade-off values are calculated for the a.m. and p.m. commutes. Commuters who experienced longer travel times were more likely to change their departure times. When changing departure times, females and managers were less likely to depart from home later than usual, and managers were also more likely to depart earlier than usual. To analyze relationships empirically, ordinary-least-squares and tobit models of departure time are estimated. Finally, the implications are discussed.
Comprehensive Planning Model for Ferry Ridership Forecasting Analysis in Puget Sound Region
Authors: Dehghani Youssef , Saranathan Krishnan , Gihring Céline
Published: April 2007

The methods used to develop a travel forecasting model for the Washington State Ferries (WSF) are described. The model is being used to develop ridership forecasts for the WSF Long-Range System Plan and other project planning efforts. The WSF model covers a 12-county ferry system service area, including the four counties within the central Puget Sound region. The model was designed to be sensitive to policy variables and to produce detailed ridership forecasts on each ferry route by ( a) boarding methods, ( b) mode of access and egress combinations for walk-on passengers, and ( c) vehicle occupancy for those persons boarding by vehicle. The model is fully incremental and uses observed travel patterns from a comprehensive on-board origin-destination survey of ferry riders conducted in 1993 for the afternoon peak period. Choice of terminal is an intermediate destination choice for walk-on ferry riders and is a prime example of trip chaining between an origin and destination. A new method involving matrix algebra has been used to formulate choice of terminal in terms of matrix products. This method estimates demand matrices corresponding to individual legs of the trip chain for each access and egress mode combination. The modeling system was validated for replication of ridership on each route by boarding methods and by mode of access and egress combinations.
Allocation of Pavement Damage Due to Trucks Using a Marginal Cost Method
Authors: Hajek Jerry J. , Tighe Susan L. , Hutchinson Bruce G.
Published: April 2007

A procedure was developed for quantifying the pavement cost of proposed changes in regulations governing truck weights and dimensions, particularly the marginal cost method used for pavement cost allocation. The procedure was part of a comprehensive study undertaken by the Ontario Ministry of Transportation in response to government and industry initiatives to harmonize Ontario’s truck regulations with those in surrounding jurisdictions. The marginal pavement cost of truck damage was defined as a unit cost of providing pavement structure for one additional passage of a unit truckload (expressed as equivalent single axle load). The results indicate that the highway type (or truck volumes associated with the highway type) has a major influence on marginal costs. For example, the annualized pavement life-cycle cost of the passage of one additional typical truck on 1 km of a highway in southern Ontario can range from about $0.004 for a freeway to $0.46 for a local road (Canadian dollars). The marginal cost method can be used to quantify pavement damage due to any axle load combination for both new and existing, in-service pavements. The knowledge of marginal costs would enable highway agencies to quantify the impact of specific regulatory changes of truck axle weights on pavement costs; for example, to quantify the pavement costs associated with increasing allowable truck weights of logging trucks on a specific segment of the highway network.
Simulation Modeling of Electronic Screening at Weigh Stations
Authors: Kamyab Alireza , Maze Tom , Nelson Mark , McCall Bill
Published: April 2007

Electronic screening of trucks before reaching points of regulatory compliance checks (typically, weigh stations) would allow for more efficient use of government resources while reducing travel time for motor carriers. A study was done of the effects of electronic screening on reducing travel time and enhancing productivity of the weigh station using a new simulation model. The model illustrates the impact of electronic screening on motor carrier travel time savings and weigh station productivity assuming various levels of transponder-equipped vehicles. The results indicate that as participation grows, enforcement agencies and participating (transponder-equipped) and nonparticipating trucks all share in the benefits afforded by a more efficient system.
Parks Highway Load Restriction Field Data Analysis: Case Study
Authors: Raad Lutfi , Johnson Eric , Bush Dave , Saboundjian Stephan
Published: April 2007

The loss of pavement strength during spring thaw could result in excessive road damage under applied traffic loads. Damage assessment associated with the critical thaw period is essential to evaluate current load restriction policies. The Alaska Department of Transportation and Public Facilities proposed a plan that will provide an engineering analysis of field conditions with 100-percent loads on the Parks Highway for 1996. Extensive data were collected and analyzed in an effort to monitor pavement damage during the spring of 1996 and to determine loss of pavement strength. Field data included truck traffic data from scalehouse and weigh-in-motion (WIM) stations, pavement temperature data, profilometer data for roughness and rutting, and falling weight deflectometer data. Analyses were performed to compare WIM and scalehouse traffic data and to determine the fraction of overweight axle-loads and corresponding pavement damage during spring thaw. Northbound and southbound truck traffic and its effect on pavement damage were considered. Ground temperature measurements were analyzed to determine when thaw initiates and how long seasonal load restrictions are required. In addition, comparisons of remaining life with and without load restrictions using mechanistic methods were conducted.
Comparison of Disaggregate Simplicial Decomposition and Frank-Wolfe Algorithms for User-Optimal Route Choice
Authors: Tatineni Maya , Edwards Henrik , Boyce David
Published: April 2007

The disaggregate simplicial decomposition (DSD) method has been posed as a better alternative to existing algorithms for solving the deterministic user-optimal route choice model. The application of the DSD algorithm is compared and evaluated with the commonly used Frank-Wolfe (FW) algorithm on a large network in the Chicago area. The results indicate that the DSD algorithm performs much better than the FW with respect to reaching the optimality conditions specified by the model.
On-Line Vehicle Routing with Time Windows: Optimization-Based Heuristics Approach for Freight Demands Requested in Real-Time
Authors: Shieh How-Ming , May Ming-Der
Published: April 2007

The problem of the on-line version of the vehicle routing problem with time windows (VRPTW) differs from the traditional off-line problem in the dynamical arrival of requests and the execution of the partial tour during the run time. The study develops an on-line optimization-based heuristic that combined the concepts of the “on-line algorithm,” “anytime algorithm,” and local search heuristics to solve the on-line version of VRPTW. The solution heuristic is evaluated with modified Solomon’s problems. By comparing with these benchmark problems, the different results between on-line and off-line algorithms are indicated.
Major Investment Studies and Environmental Documentation: Clearing Up the Confusion
Authors: Emerson Donald , Benz Greg
Published: April 2007

Federal planning regulations issued in 1993 require major investment studies (MISs) to help metropolitan planning organizations reach decisions on high-cost, high-impact highway and transit facilities. The regulations offer two options for the development of National Environmental Policy Act (NEPA) documents for major investments. In Option 1, draft and final NEPA documents are prepared during the project development/ preliminary engineering phase for any projects that emerge from an MIS and have been incorporated into the region’s long-range plan. In Option 2, a draft NEPA document is prepared as part of the MIS. Although there is general appreciation and understanding of the planning principles underlying the MIS process, the role of environmental impact analysis and documentation has been a source of confusion, misunderstanding, and skepticism. An attempt is made to clear up this confusion by explaining Option 1, Option 2, and the more recently conceived Option 1½ and by presenting situations and circumstances in which each option might be most advantageous. Also presented is the federal “vision” that led to the development of the MIS process, the nature of MIS alternatives is highlighted, suggestions for establishing the appropriate level of detail are offered, and a distinction is made between NEPA principles and documentation requirements.
Innovative Sampling Plans for Estimating Transit Passenger-Kilometers
Authors: Furth Peter G.
Published: April 2007

Estimating passenger-kilometers or passenger-miles to meet National Transit Database requirements usually involves costly sampling. Three innovative sampling plans are described that have been developed to reduce sampling requirements. The first method, which proved to be very effective when total boardings is known, uses a small number of ride checks (ons and offs by stop) on each route. Average trip length is estimated as a combined ratio estimator from a stratified sample. The second method was applied where the boardings total is not known. It uses both a sample of ride checks and another sample (needed for another purpose) that measures only boardings. A “mixed estimator” is derived that optimally combines two separate estimators: a simple mean from the ride check sample and an average trip length from the ride check sample multiplied by average boardings from the other sample. This second method proved effective for a single light-rail line but only marginally effective for a large bus system with widely varying route lengths. The third method exploits the pattern of symmetry in boarding and alighting patterns in opposite directions to estimate average trip length by route using boardings data only. Average trip length is the algebraic difference between the boardings centroids in the two directions. For the two routes analyzed, this method turned out to be ineffective in comparison with other methods because of high between-trip variability in the boardings centroids.
Aggregate Degradation Testing by Gyratory Testing Machine
Authors: Ruth Byron E. , Tia Mang
Published: April 2007

The Gyratory Testing Machine (GTM) equipped with an air roller was used to investigate the dry and wet degradation of six aggregates. Three gradings similar to those for the Los Angeles (LA) abrasion test were evaluated in the GTM by using 25, 50, 100, and 200 revolutions. The test data indicated substantial differences in gradation of the aggregates after testing. Type and initial size of the aggregate influenced the amount and characteristics of degradation. Regression analyses of the data resulted in the development of GTM degradation prediction equations using the LA abrasion loss. The most important goal for the GTM test results was to define gradation and the effect of moisture, instead of using only a relative indicator such as LA abrasion loss. Four aggregate blends were tested in the GTM to simulate degradation produced in handling and processing of aggregate through a drum mixer and drum dryer. These test results duplicated some of the gradations obtained after the material had passed through the drum.
Aggregate Rugosity and Size Effect on Bituminous Mixes
Authors: Khedaywi Taisir S. , Tons Egons
Published: April 2007

Higher costs and possible restricted availability of asphalt have stimulated research and discussion on how to reduce the amount of asphalt in bituminous mixes without sacrificing service. A hypothesis was proposed suggesting that for each coarse aggregate type with different surface characteristics there is a specific fine aggregate size that contributes to developing an interlocking mechanism between the surfaces of coarse aggregates when they are combined in a bituminous mix. To test this hypothesis, two types of coarse aggregates having different surface characteristics or rugosity, limestone and rounded gravel, were used. For each aggregate, two one-size fractions were tested—19 mm to 25 mm and 6.4 mm to 4.75 mm. One type of fine aggregate (limestone) with five one-size fractions was used. Four flow binder film thicknesses were chosen. The packing volume and rugosity concepts were the theoretical basis. Asphalt and aggregate mixes were tested in compression. The results were evaluated by the use of regression equations. Graphical presentations and illustrations were used as necessary. Unconfined compression test results showed that for one-size limestone coarse aggregate, the highest strength values were associated with No. 60 to No. 80 fines in the mix and for one-size rounded gravel coarse aggregate, the highest strength occurred when No. 200 to No. 270 fines were added to the mix. The highest strength was associated with 50 μm flow binder film thickness for all mixes.
Performance Evaluation of Highway Embankment Constructed with Waste Foundry Sand
Authors: Partridge Barry K. , Alleman James E. , Fox Patrick J. , Mast David G.
Published: April 2007

Considerable savings are possible for the metal casting industry through the development of reuse applications for waste foundry sand (WFS). State departments of transportation face increased pressure to reuse waste materials in transportation construction. In 1996, the Indiana Department of Transportation and Purdue University constructed a demonstration embankment by using WFS from a ferrous foundry. WFS and control embankments were instrumented to monitor geotechnical and environmental performance during and after construction. Stockpile and jobsite WFS samples also were tested. The geotechnical investigation demonstrated that WFS can perform well as a structural fill, having strength and deformation characteristics comparable to natural sand. The compacted WFS has a hydraulic conductivity considerably lower than that of natural sand and generally cannot be considered as freely draining. Environmental testing consisted of Microtox and Nitrotox bioassays, ion chromatography, and inductively coupled plasma testing for metals. Bioassay results indicate the WFS has not leached contaminants at concentrations higher than those expected from natural sand and is not likely to have a negative environmental impact at the site. Ion migration from the WFS into the foundry sand lysimeter was found, supporting bioassay data, but at concentrations below drinking water standards or reuse regulatory criteria. Metal concentrations typically were below detection levels.
Gradation and Moisture Effects on Resilient Moduli of Aggregate Bases
Authors: Tian Ping , Zaman Musharraf M. , Laguros Joakim G.
Published: April 2007

Resilient modulus ( M R) which properly characterizes the load-deformation response of pavement materials under traffic loading, is evaluated. The M R values due to three different gradations and three different moisture contents were investigated for the Richard Spur and the Sawyer aggregates, which are commonly used in Oklahoma as the subbase or base materials of roadway pavements. The three gradations were finer limit, median, and coarser limit, as specified by the Oklahoma Department of Transportation for Type A aggregate. The three moisture contents selected are optimum moisture content (OMC), 2 percent below OMC, and 2 percent above OMC. To investigate the variability of the test results, six duplicate M R tests under identical conditions were performed for each case by using the AASHTO T294-94 method. Furthermore, the material properties, K1 and K2, which are required input in the AASHTO pavement design equation, were evaluated for the M R values obtained. Finally, multiple linear regression models for predicting the M R values of the two aggregates were established.
Weighting Factor for Seasonal Subgrade Resilient Modulus
Authors: Guan Yun , Drumm Eric C. , Jackson N. Mike
Published: April 2007

Subgrade resilient modulus is highly dependent on water content, which can vary significantly with a number of seasonal environmental factors. Because the determination of seasonal resilient modulus is cumbersome, it is difficult to include environmental factors in pavement design. The use of a weighting factor for flexible pavement design to include the effects of monthly changes in the subgrade resilient modulus is described. The weighting factor, which was derived from Miner’s linear damage concept and the 1993 AASHTO design equation for flexible pavements, is used to designate a design season. Instead of using multiple values of resilient modulus in the pavement design process, the pavement design may be performed with a single value of subgrade modulus corresponding to this design season. A pavement design based on this design season then is assumed to reflect the seasonal variations in subgrade modulus and the corresponding relative damage that the pavement would sustain over al seasons of the year. The weighting factor can be calculated from laboratory tests of resilient modulus over the range of water contents that may be encountered in the subgrade over different seasons. Alternatively, the weighting factor can be obtained from the resilient modulus backcalculated from seasonal nondestructive tests. The determination of the weighting factor and the design season resilient modulus was demonstrated in three examples and shown to be consistent with the recommendations of the 1993 AASHTO guide. The use of the weighting factor should provide a cost-effective means of including seasonal variations in subgrade properties while minimizing the required number of laboratory resilient modulus tests.
Comparative Analysis of Spatial Knowledge and En Route Diversion Behavior in Chicago and San Francisco: Implications for Advanced Traveler Information Systems
Authors: Khattak Aemal J. , Khattak Asad J.
Published: April 2007

Drivers’ spatial knowledge and en route response to unexpected delay information are examined. Compared are behavioral responses to information across two metropolitan areas in the United States: Chicago and the San Francisco Bay Area. Comparable behavioral data were collected through handout-mailback questionnaires targeting peak-period automobile commuters. The Chicago respondents perceived higher traffic congestion levels, and more of them knew one or more alternate routes. Among the Chicago respondents, fewer received information about unexpected delays from the radio (as opposed to self-observation of congestion) and more automobile commuters diverted to their alternate routes. To understand the factors that influence knowledge of alternate routes and en route diversion in response to unexpected congestion, a full information maximum likelihood nested logit model is estimated. Results of the model indicate that longer duration of residence, higher propensity for discovering new routes, and locational characteristics tend to increase drivers’ spatial knowledge. Propensity for en route diversion increases with higher than usual route travel time plus delay and shorter alternate route travel times. Drivers with higher propensity for taking risks to avoid unexpected delays are more likely to divert. The model indicates that route knowledge and en route diversion propensity is higher in Chicago than San Francisco. This implies that information-sensitive behavioral models may be context dependent. Importantly, delay information received through radio traffic reports, as opposed to other sources such as self-observation of congestion, increases en route diversion propensity in unexpected delay situations. This implies a more dynamic readjustment of commuters’ route selection decisions. At the same time, the potential benefits from Advanced Traveler Information Systems (ATIS) must compete with the benefits already accruing from radio traffic information.
Evaluation of an Automated Airport Ground Transportation Information System
Authors: Gosling Geoffrey D.
Published: April 2007

Described are the results of an evaluation study of a demonstration program sponsored by the Division of Aeronautics of the California Department of Transportation, in which computer-based ground transportation information kiosks were installed in four California airports, in conjunction with a similar program undertaken by the Los Angeles Department of Airports. The study included an analysis of kiosk-use patterns derived from the logfiles of user keystrokes and various system actions, which are automatically maintained by the kiosks, and surveys of both kiosk users and airport users in general to determine traveler awareness of the new information kiosks, identify passenger ground transportation information needs, evaluate user satisfaction with the information provided, and determine general travel characteristics of kiosk users. Finally, the costs involved in routine operation and in maintenance of the kiosks are examined and a number of recommendations are made on the future use of the kiosks and on the need to preserve the information generated by the demonstration program.
Relationships Between Airport Activity and Ground Transportation Needs
Authors: Shapiro Phillip S. , Katzman Marcy
Published: April 2007

Shortly after the passage of the Intermodal Surface Transportation Efficiency Act of 1991, the Federal Highway Administration and the Federal Aviation Administration recognized that there was very little guidance available for airport operators and metropolitan planning organizations (MPOs) to use for planning intermodal access to airports in the United States. As a result, the Intermodal Ground Access to Airports: A Planning Guide was developed. This Guide is designed to provide guidance to states, MPOs, and airport operators on the types of analyses that should be performed when airport access is being planned. It describes the airport access planning process and procedures for performing analyses. During the development of the Guide, relationships were developed between the level of originating passengers at American airports and the characteristics of airport access and landside facilities. The types of characteristics that were related to originating passengers included public parking, vehicle trips, terminal curbside design, and mode of access. Some of the relationships that were developed, how they were derived, and their importance to airport access planning are now presented. In addition, some additional relationships that should be developed are suggested.
Assessment of the Relationship Between Productivity and Performance Quality in the U.S. Domestic Airline Industry
Authors: Ozment John , Morash Edward A.
Published: April 2007

Output quality in the context of transportation productivity is investigated. The major findings relate to two distinctions: network density versus capacity utilization and productivity versus input cost efficiency. It was found that greater transportation network density is associated with increased productivity, lower output costs, and most interestingly, improved output quality. In contrast, increased capacity utilization is not associated with lower output costs or with improved quality. For the productivity versus efficiency distinction, increased productivity is associated with lower total output costs and greater output quality yet higher input costs. Thus, higher factor input costs can be justified on the basis of output costs and quality advantages. Implications for governmental policy and managerial decision making are that improvements in network density and productivity are more likely to have lasting benefits than are increases in capacity utilization or input efficiency.
Use of Air Transportation by Business and Industry in Minnesota
Authors: Braslau David , Johns Robert C.
Published: April 2007

Current and forecasted use of air transportation by businesses in Minnesota using the Standard Industrial Classification is described. The research is based upon a study on air service and commercial and industrial activity in Minnesota required by the Minnesota legislature in 1996. Purchases from the air transportation sector that includes scheduled and nonscheduled passenger and freight services are based upon the 1993 IMPLAN input-output model for Minnesota and Bureau of Economic Analysis (BEA) and Bureau of Labor Statistics (BLS) forecasts for Minnesota. In addition to intraindustry transfers within the air transportation sector, purchases of air transportation are dominated by business associations, management and consulting services, and the U.S. Postal Service sectors. These four sectors also represent the sectors with the largest share of purchases of air transportation. BLS historical and forecast data suggest that the major group of industries that purchased air transportation in 1977 will remain intact through 2005. Under BEA forecasts for Minnesota, air transportation purchases by all industry sectors will increase more rapidly than other transportation modes. BEA also forecasts the air transportation component of gross state product growing faster than forecasted passenger originations at Minneapolis–St. Paul (MSP). The implications of the BEA forecasts will be considered in the next update of activity forecasts for MSP. This research is considered only the first step in understanding the role of air transportation to commerce and industry in Minnesota and other states.
Models for Predicting Bus Delays
Authors: Abdelfattah Ali M. , Khan Ata M.
Published: April 2007

The provision of accurate bus arrival time information to users is essential for improving the attractiveness of public transit service. Although bus-tracking technology provides real-time information to the control center about the location of a bus, there is a need to improve the prediction of bus travel time downstream from location of last observation in mixed traffic operations. Methods are required for making predictions in normal traffic conditions, as well as in conditions in which a temporary lane closure is experienced due to a variety of reasons, such as incidents and road improvement activities. The development of models for the estimation of the effect of changes in traffic and lane closures on bus performance is described. A microsimulation approach was used, supplemented by field studies. The models developed meet calibration tests and were verified by field data.
Transitioning to Fixed-Route Services
Authors: Denson Carol R.
Published: April 2007

By 2002, it is expected that all fixed-route transportation systems in the United States will be accessible to people with disabilities. This is heralded as good news for riders who have been limited to traveling via special services (i.e., paratransit) and transit providers concerned with the cost of such services. Such optimism assumes—perhaps erroneously—that many riders will shift from paratransit to the newly accessible fixed-route systems. A survey was conducted that reveals that riders are generally satisfied with the service they receive and—despite imminent accessibility—are not eager to switch. The paratransit service, which the Americans with Disabilities Act (1990) regards as a “safety net” for those unable to use fixed-route transit, has become the primary mode of public transport for significant portions of its ridership. However, a core group of riders appears to be interested in changing, which, coupled with the finding that almost none of the survey respondents had received any form of travel training, suggests that there is cause for measured optimism. In addition to training, accessibility must be considered in systemic terms, built on the requirements that riders know how to use the fixed-route system and can get to and from buses, they believe they are welcome in the system, and they understand the costs and consequences of using paratransit. These results are achievable by educating riders, transit staff, and the general public. In addition, there needs to be informed manipulation of fixed routes.
From Commuter Rail to Regional Rail: Operating Practices for the 21st Century
Authors: Allen John G.
Published: April 2007

Several low-cost, low-technology measures can upgrade service levels and reduce unit costs of operation on commuter railroads. By gradually implementing one-person operation and other techniques borrowed from rapid transit, busier commuter rail properties can emulate the frequency and comfort of such modern regional rail transit lines as the Port Authority Transit Corporation, Bay Area Rapid Transit, and the Washington Metro. Metra Electric (formerly the Illinois Central Electric) offers an example of how these measures might be implemented. In their heyday, the Illinois Central Electric and other commuter railroads provided service of similar quality to today’s regional rapid transit lines. Today these commuter lines operate at needlessly low levels of efficiency, but these measures should help commuter railroads develop their potential. The result should be a win-win situation: more efficiency for management, more jobs for labor (as a result of more frequent service), and more service for customers.
The Golden Proportion and Aesthetic Design of Long-Span Bridges
Authors: Yee Ronald
Published: April 2007

In recent years there has been a revival in the debate between architects and engineers about the aesthetics of bridges and who should be responsible for designing them. This subject is examined, and it is suggested that an understanding of the basic concepts, common sense, and cooperation among professionals are all necessary for pleasing designs. Good harmonious proportions in three-dimensional space are essential for achieving aesthetic beauty. This is particularly true in the design of long-span bridges. It is not sufficient for bridges to be just functional and mathematically correct, nor is it acceptable for the advantages of modern construction to be exploited for economic benefit without due consideration of aesthetics and the environment. Since earliest times, structures and buildings that have become universally accepted as good examples of aesthetic beauty have good proportions as the foundation of their design. Countless proportional theories have been proposed in the search of aesthetic beauty, each finding favor from time to time. However, only the Golden Proportion is based on the dimensions and ratios of the human form. By illustrating how proportion has been incorporated into the composition of some recent bridges, it is found that the appropriate use of proportion accompanied by creative thought and judgment can result in aesthetic structures.
Behavior of High-Density Polyethylene Pipe with Shallow Cover
Authors: Phares B. M. , Wipf T. J. , Klaiber F. W. , Lohnes R. A.
Published: April 2007

In this investigation, a testing program was initiated to gain some understanding of the nature of high-density polyethylene (HDPE) as a structural material and as a buried structure. The testing program consisted of a series of parallel plate tests, a sequence of flexural tests, and field tests of buried pipes under varying backfill conditions. Parallel plate tests were conducted in accordance with ASTM D2412. The flexural testing consisted of applying two point loads to simply supported beam specimens. The field tests completed in this investigation were developed to study the response of large-diameter HDPE to concentrated loads under shallow cover. From the testing, it seems that in cases where high longitudinal stresses may be present (concentrated loads with shallow cover, uneven bedding, uplift, etc.) the pipeline designer should consider the longitudinal strength of HDPE pipes in addition to the circumferential and backfill properties. In addition, the designer must realize that when stresses exist in both directions, the Poisson’s ratio effect must be considered. This finding is supported by the longitudinal failure strains measured during the flexural tests and the field tests. In both types of tests, the pipes failed at approximately the same longitudinal strain level, approximately 1,300 microstrain. On the other hand, in the field tests, the pipes never reached the magnitude of strain associated with failure in the laboratory parallel plate tests.
Design of Automatic Comprehensive Traffic Data Management System for Pennsylvania
Authors: Chung Jin-Hyuk , Viswanathan Krishnan , Goulias Konstadinos G.
Published: April 2007

With the highway infrastructure under strain, there is a need to collect and analyze traffic volume, vehicle classification, and weight data in an integrated manner. Most research focuses on collection and quality of data with little emphasis on an integrated traffic data management system. Design of an integrated traffic data management system that allows for editing, storage, and reporting of traffic volumes, vehicle classification, and vehicle weight along with quality assurance of data is presented. The system includes the creation of new software and the use of existing software that has been modified to allow for the flagging of data errors, the reading of 1995 Traffic Monitoring Guide format data, and the aggregation of vehicle class data in suitable schemes to ease analysis. Procedures for the input of missing data and the correction of erroneous data are described. The system is user friendly and designed to operate under a Windows 3.1 or a Windows NT 4.0 environment. Refinements needed in the future are identified and presented.
Geostationary Satellite Coverage for Surface Applications of Differential Global Positioning system
Authors: Arnold James A.
Published: April 2007

The coverage issues surrounding the use of geostationary satellites for surface applications using Differential Global Positioning System (DGPS) data are examined. The Federal Aviation Administration’s Wide Area Augmentation System plan to use geostationary satellites to provide differential corrections for aviation users is presented. Impediments to coverage include man-made structures, irregular terrain (i.e., mountains), and attenuation or signal fading due to tree canopy. Each of the impediments is examined and an assessment is made of their effects on coverage. Various user groups require ubiquitous coverage, and a geostationary satellite broadcast of corrections does not provide this. Large gaps will exist in rural and urban areas, and signal fading due to tree canopy will be significant over much of the country. Alternative communication techniques, such as the U.S. Coast Guard Low Frequency Radiobeacon DGPS service, should be used to meet surface user requirements.
Experimental Application of Global Positioning system To Locate Motor Vehicle Crashes: Impact on Time and Accuracy
Authors: Miller John S. , Karr Duane
Published: April 2007

Motor vehicle crash countermeasures often are selected after an extensive data analysis of the crash history of a roadway segment. The value of this analysis depends on the accuracy or precision with which the crash itself is located. yet this crash location only is as accurate as the estimate of the police officer. Global Positioning System (GPS) technology may have the potential to increase data accuracy and decrease the time spent to record crash locations. Over 10 months, 32 motor vehicle crash locations were determined by using both conventional methods and hand-held GPS receivers, and the timeliness and precision of the methods were compared. Local crash data analysts were asked how the improved precision affected their consideration of potential crash countermeasures with regard to five crashes selected from the sample. On average, measuring a crash location by using GPS receivers added up to 10 extra minutes, depending on the definition of the crash location, the technology employed, and how that technology was applied. The average difference between conventional methods of measuring the crash location and either GPS or a wheel ranged from 5 m (16 ft) to 39 m (130 ft), depending on how one defined the crash location. Although there are instances in which improved precision will affect the evaluation of crash countermeasures, survey respondents and the literature suggest that problems with conventional crash location methods often arise from human error, not a lack of precision inherent in the technology employed.