bluuebunny/crossref_metadata_2025 huggingface dataset:
MOBILE Matrix: Application of Georgia Statewide Multimodal Transportation Planning Tool for Rural Areas
Authors: Guensler Randall L. , Dixon Karen K. , Elango Vetri Venthan , Yoon Seungju
Published: April 2007

The U.S. Environmental Protection Agency's MOBILE emission rate model is used to evaluate carbon monoxide, hydrocarbon, nitrogen oxide, and particulate matter impacts of major transportation projects. Using fleet characteristics, environmental conditions, and on-road operating conditions, MOBILE estimates fleet average emission rates. Coupling projected traffic volumes and physical roadway characteristics yields pollutant mass flux rates with which dispersion models predict downwind pollutant concentrations. Distance-flux relationships may also prove useful in pollutant exposure modeling to help quantify relative environmental risks of living or working near major roadways. Applying the MOBILE model requires the creation and execution of scenario-specific input files, which must be properly structured. Researchers developed the MOBILE-matrix model to facilitate more readily the use of MOBILE emission rates in transportation modeling. The matrix creates large emission rate lookup tables that can be applied to traffic in any facility or subregion. It performs all necessary model runs well before a future modeling need. The goal of this specific application is to integrate MOBILE-matrix capabilities into the multimodal transportation planning tool (MTPT) employed by the Georgia Department of Transportation so that it can be used to estimate emissions from rural road facilities throughout the state. Thousands of MOBILE6.2 runs were executed to generate database output files, which were post-processed to create MOBILE-matrix lookup tables for 159 Georgia counties. For each transportation link in the MTPT, emission rates are extracted from the lookup matrix by facility type, average speed, temperature, and so forth. The predicted emissions can then be used for a variety of transportation planning purposes.
Methodology for Deriving Vehicle Activity Parameters from Travel Survey Databases
Authors: Chalumuri Soujanya , Venigalla Mohan M.
Published: April 2007

Vehicle activity parameters are key inputs to mobile source emissions modeling. Emission factors are sensitive to these inputs, which vary by geography, time of day, and trip purpose classifications. The state of the practice in emission factor modeling relies heavily on default parameters imbedded in the models. Therefore, there is a need for deriving these inputs for the various geographic regions to provide realistic values. Methods are described for deriving vehicle activity parameters from travel surveys, such as starts distribution, fraction of vehicle miles traveled (VMT), trip length distribution, soak time distributions, and the VMT mix distribution. This methodology is applied for deriving vehicle activity parameters from Nationwide Personal Transportation Survey databases and conducting a sensitivity analysis of the MOBILE6 model with respect to these derived inputs. Inputs derived from travel surveys are compared with MOBILE6 default inputs; wide variations in the inputs are observed. A sensitivity analysis of MOBILE6 related to travel survey inputs reveals that emission factors can vary by as much as 26% when compared with those obtained with default inputs. A statistical analysis has determined that the difference in emission factors is significant enough to warrant the development of locale-specific inputs.
Using Geographic Information Systems to Evaluate Siting and Networks of Hydrogen Stations
Authors: Nicholas Michael A. , Handy Susan L. , Sperling Daniel
Published: April 2007

The lack of hydrogen fuel stations is a major barrier to the introduction of hydrogen vehicles. Given the high cost of constructing hydrogen stations, it is desirable to build as few stations as possible while still adequately serving consumers. Although several studies have addressed the general question of how many stations are needed, the literature has been largely silent on how to relate the location of stations to the sufficient number of hydrogen stations. A geographic information system (GIS) provides a tool for evaluating station siting decisions as part of a greater hydrogen network. A GIS model was developed for siting generic hydrogen stations in Sacramento County, California, with the economics of supplying those stations with hydrogen ignored for now. The analysis used average one-way driving time from home or work to a station as a metric to evaluate scenarios. When a network is posited with 30% as many retail fuel stations as now exist, average driving time from home to a station would be 16 s more than it is with the full existing network of stations. With 5% of existing stations supplying hydrogen (or any other alternative fuel), the average driving time to a station could be as little as 4 min in Sacramento County. These estimates assume free-flow traffic; actual times will vary. This modeling approach provides an analytical framework for siting early hydrogen fuel stations. Initial results suggest a few strategically sited stations could be sufficient to satisfy a large number of prospective consumers.
Sound Levels and Shadow Zones Behind Barriers in Florida
Authors: MacDonald J. , Wayson R. , EI-Aassar A. , Berrios M.
Published: April 2007

A description is given of new results based on measurements of 19 noise barriers in the state of Florida and the innovative techniques used during data analysis. This work is a continuation of an ongoing study of noise barrier effectiveness in Florida. A new empirical method was developed to estimate the length of shadow zones behind highway noise barriers. This new method can lead to more effective design of future highway noise barriers. The method required an estimate of location and strength of a simulated background source to determine a more realistic edge of the shadow zone. This work also produced custom software that estimates and graphs the formation of shadow zones behind barriers, given readily available site information.
Locomotive Horn Effectiveness at Operating Speeds
Authors: English Gordon W. , Moore Thomas N.
Published: April 2007

One aspect of a study undertaken for Transport Canada—as a component of the joint government- and industry-funded Direction 2006 Highway-Railway Grade Crossing Research Program—is addressed. The study's objective was to provide recommendations to ensure adequate warning for safety reasons and to address excessive loudness complaints from crews and from residents near tracks. A description is given of the field measurements and analyses undertaken to assess the influence of horn position on the effectiveness of the horn at operating speeds; an in-service assessment of alternative horns is also presented. Conclusions and recommendations are made to reposition horns in new-build locomotives and to add emergency-only or two-level horns at the front of some models of existing locomotives.
Influence of Speeds on Design Standards in Switzerland
Authors: Spacek Peter
Published: April 2007

In Switzerland, a speed diagram is used to check the consistency of the alignment of a section of highway. The sequence of alignment elements is subject to maximum permitted differences for the design speed, and the highest design speed is coupled to the general speed limit applicable to the category of highway in question. After a significant reduction in the speed limit for rural highways [100 to 80 km/h (62 to 50 mph)], the application of this model as a control instrument in practice has become problematic. Consideration is being given to an alternative procedure, such as specifying the permitted radii sequence. The analysis deals principally with the changes in speed behavior compared with previous surveys from the period when a higher speed limit was in place. The main focus of this study was the relationship between curve radius and running speed; the influence of other design elements in curves and speed behavior on curves on rural highways were also investigated. The alignment model in Swiss geometric design standards is described. On the basis of the new findings, the problems of the Swiss alignment model and the implications for existing design standards were analyzed.
Lengths of Double or Dual Left-Turn Lanes
Authors: Kikuchi Shinya , Kii Masanobu , Chakroborty Partha
Published: April 2007

Double (or dual) left-turn lanes (DLTLs) are a relatively new geometric feature, and the literature on their design parameters is limited. The effectiveness of the DLTL in improving the operation of an intersection depends on several design parameters; among them, the most critical is the length of the DLTL. A procedure for determining the length of the DLTL was developed. First, the procedure surveys how drivers choose a lane of the DLTL in the real world and analyzes the relationship between lane use and the volume of left-turn vehicles. Second, the procedure formulates the probability that all arriving left-turn vehicles during the red phase can enter the left-turn lanes; this means no overflow of left-turn vehicles from the DLTL and no blockage of the entrance of the DLTL by the queue of through vehicles. This probability is presented as a function of the length of the DLTL and the arrival rates of left-turn and through vehicles. The adequate lane length is derived such that the probability of the vehicles entering the DLTL is greater than a threshold value. Third, the adequate length is expressed in number of vehicles; later, this value is converted to the actual distance required on the basis of the vehicle mix and preference between the two lanes. Recommended lengths are presented as a function of left-turn and through volumes for practical application. The proposed approach is unique in that it avoids lane overflow and blockage of lane entrance.
Sequential Logit Dynamic Travel Demand Model for Hurricane Evacuation
Authors: Fu Haoqiang , Wilmot Chester G.
Published: April 2007

Little attention has been given to estimating dynamic travel demand in transportation planning in the past. However, when factors that influence travel are changing significantly over time, such as with an approaching hurricane, dynamic demand and the resulting variation in traffic flow on the network become important. The decision to evacuate in the face of an oncoming hurricane is considered as a series of binary choices over time. A sequential binary logit model is developed to model the probability that the members of a household will evacuate at each time period before hurricane landfall as a function of the household's socioeconomic characteristics, the characteristics of the hurricane, and policy decisions made by authorities as the storm approaches. Data collected in southwest Louisiana after Hurricane Andrew were used to estimate a model that produced dynamic travel demand estimates of hurricane evacuation. On the basis of the results, a sequential logit model appears to be capable of modeling dynamic evacuation demand satisfactorily.
Optimal Tolls with a Multiclass, Bicriterion Traffic Network Equilibrium
Authors: Yin Yafeng , Yang Hai
Published: April 2007

The feasibility of the so-called marginal-cost pricing principle for providing an anonymous link toll (uniform toll across all individuals) pattern in a network with multiple user classes is investigated. The social and spatial inequality issues caused by the anonymous tolling are also addressed. It was assumed that the classes of users differed from one another in un-observable ways: they placed different values on the same amount of money, and they perceived travel disutility in money or time units. These characteristics precluded the possibility of nonanonymous or discriminatory tolling. Specifically, answers to the following questions were sought. Was the bicriterion user equilibrium flow the same as the single-criterion (in time or monetary units) flow in the presence of road pricing? Did the marginal-cost pricing principle suggest an anonymous link toll pattern that could support the multiclass, bicriterion user equilibrium flow pattern as a system optimum? In addition, models for selecting the most equitable anonymous link toll pattern that could lead to a system optimum were derived.
Estimation of Turning Movements at Intersections: Joint Trip Distribution and Traffic Assignment Program Combined with a Genetic Algorithm
Authors: Nakatsuji Takashi , Nakano Kenji , Nanthawichit Chumchoke , Suzuki Hironori
Published: April 2007

The availability of turning movement data at intersections is essential in carrying out traffic simulations with software such as NETSIM. However, data collection is very time-consuming even for a small network. To estimate turning movements at intersections, a logit-based stochastic user equilibrium (SUE) model was integrated into a genetic algorithm. Three derivative models were developed: ( a) a doubly constrained estimator, ( b) a singly constrained estimator, and ( c) an origin-destination (O-D)-based estimator. In the first and second estimators, the SUE model was formulated as a joint trip distribution and traffic assignment (TD-TA) program, whereas in the third estimator, the SUE model was based on a standard O-D distribution program. These turning movement estimator models were examined by applying them to three road networks: a virtual road network with simulated data, a small road network in the field with data obtained by manual counting, and a road network with data measured with traffic detectors. Application of the models to the virtual road network proves that if prior information on the O-D distribution is available, the O-D-based estimator is most effective in estimating turning movements. Application of the models to real networks for which no prior information on the O-D flows is available shows that the doubly constrained TD-TA-based model is the most accurate and efficient. The turning movements on major links estimated with this model were in relatively good agreement with those actually measured. The correlation coefficient of link flow exceeded 0.90. However, the rationale of the range of unknown variables remains unresolved.
Combinatorial Approach for Multiple-Destination User Optimal Dynamic Traffic Assignment
Authors: Golani Hina , Waller S. Travis
Published: April 2007

An algorithm that can be used to solve the user optimal dynamic traffic assignment problem for multiple destinations is proposed. The algorithm uses the cell transmission model, which can account for traffic realities, such as dynamic queuing and spillover. The approach selects a destination for equilibration, fixes the paths of the vehicles assigned to the other destinations, and finds an optimal dynamic traffic assignment for the destination of interest via an extension to a previously introduced combinatorial algorithm. The spatial path set obtained for this destination is then fixed, and another destination is relaxed. The process is repeated iteratively among the destinations. The approach is guaranteed to find the user optimal solution for a single destination given any number of other fixed-path vehicles, but the approach is a heuristic for finding the multiple-destination user optimal path set. The algorithm is implemented and computationally tested for an example network, and solution properties are explored.
Methodology for Determining Vulnerable Links in a Transportation Network
Authors: Murray-Tuite Pamela M. , Mahmassani Hani S.
Published: April 2007

A bilevel formulation is developed to identify vulnerable transportation network links. The problem can be viewed as a game between an "evil entity" and the traffic management agency. At the lower level, the traffic management agency routes vehicles according to the system of optimal traffic assignment. At the upper level, the evil entity seeks to maximize disruption to the network. A key component of this formulation is the vulnerability index, which is a measure of the importance of a specific link to the connectivity of an origin-destination pair. The vulnerability index accounts for the availability of alternate paths, excess capacity, and travel time. The vulnerability indices are aggregated across all origin-destination pairs into the disruption index. This disruption index is the measure of damage to the network by which the evil entity might rank links as targets. Because the evil entity has a limited amount of resources, it cannot strike all of the potential targets and must choose among subsets of links. Four cases with different types of information availability for the evil entity and the traffic management agency are examined for a simple network. In each case, the evil entity is assumed to aim its strike at the link that has the potential to carry traffic for the most origin-destination pairs.
Dynamic Truckload Routing, Scheduling, and Load Acceptance for Large Fleet Operation with Priority Demands
Authors: Kim Yongjin , Mahmassani Hani S. , Jaillet Patrick
Published: April 2007

Dynamic load acceptance and rejection decisions in dynamic (online) truckload routing and scheduling problems with time windows when the carrier provides two classes of service are analyzed. The delivery service is classified into two types, priority and regular service, with different price rates corresponding to various customer requirements in terms of time sensitivity and price sensitivity. For this problem, a mixed-integer programming formulation is provided to solve a static version of the problem. Then, a dynamic acceptance-rejection policy is proposed and tested as a part of dynamic operation policy, in which the decision should be made on arrival of the demand or at least in a short time. This acceptance decision, based on the system state (the vehicles' locations, status, and scheduled demands) at a decision moment, represents the approximation of the expected number of vehicles able to serve future (still unrealized) priority demand. Simulation experiments conducted to evaluate the relative performance show that the proposed policy significantly improves overall profit compared with those obtained with the benchmark policies.
Predicting International Freight Flows for Trade: Simultaneous Multimodal, Multicommodity, Network Equilibrium Model
Authors: Safwat K. Nabil A. , Hasan Mohamad K.
Published: April 2007

Between 1990 and 1997 intraregional trade was very low among the member countries of the United Nations Economic and Social Commission for Western Asia (ESCWA). Their export share fell from 10.9% to 8.6% of their total world exports, and their import share rose from 9.1% to 10.4% of their total world imports. Among the main reasons were complicated, costly, and time-consuming border controls and customs formalities. To overcome these obstacles and to promote greater economic integration among its members, ESCWA developed an integrated transport system in the Arab Mashreq (ITSAM). ITSAM comprises three basic components: an integrated (multimodal) transport network, an associated information system, and a methodological framework for issue analysis and policy formulation. The present research focuses on the development of an international freight simultaneous transportation equilibrium model (IFSTEM) to predict equilibrium freight flow patterns (times and costs) that can describe the behaviors of exporters and importers of different commodities over an international multimodal network covering ESCWA member countries. IFSTEM is considered a central component of the ITSAM methodological framework. The application of IFSTEM to the prototype shows that the model satisfies the behavioral aspects of the freight system, and its solution procedure is computationally tractable. This should encourage the full implementation of IFSTEM (after its calibration process) as a policy analysis tool and a decision-support system for transport policy makers in the region. The approach can easily be extended and applied to other regions of the world.
Tabu Search Algorithm for Dynamic Vehicle Routing Problems Under Real-Time Information
Authors: Liao Tsai-Yun
Published: April 2007

Dynamic vehicle routing strategies have been widely discussed because of advances in information technologies. Dynamic vehicle routing problems are important aspects of commercial vehicle operation applications of intelligent transportation system technologies. One possible operational benefit of real-time information might be the ability to reroute commercial vehicles efficiently according to current traffic conditions. The present effort is aimed at developing a tabu-based dynamic vehicle routing algorithm under real-time information and then evaluating the algorithm in a simulation-assignment framework. Two types of information, historical information and real-time information, are considered in the tabu search algorithms to design temporal as well as spatial tabu lists for route construction and improvement. Numerical experiments conducted with the network of the city of Taichung, Taiwan, are presented to investigate dynamic vehicle dispatching and routing strategies under real-time information supply strategies and to assess the effectiveness of such strategies for traffic incidents.
Simulation Model for Real-Time Emergency Vehicle Dispatching and Routing
Authors: Haghani Ali , Tian Qiang , Hu Huijun
Published: April 2007

A simulation model for evaluation of a real-time emergency medical service vehicle response system that uses real-time travel time information and that assists the emergency vehicle dispatchers in assigning response vehicles and guiding those vehicles through noncongested routes is developed. Different response strategies are evaluated with this simulation model. These include the first-called, first-served strategy, the nearest-origin assignment strategy, and the flexible assignment strategy that uses real-time travel time information to assign and dispatch response vehicles. Different assumptions and conditions are used to test the sensitivity of the flexible assignment strategy.
Dynamic Routing Decisions for Commercial Vehicle Operations in Real-Time Traffic Conditions
Authors: Wang Hao , Lee Der-Horng , Cheu Ruey Long
Published: April 2007

The application of intelligent transportation system technologies to facilitate freight mobility requires dynamic routing decisions to reduce operational costs and enhance service levels. Although most route planning or scheduling methods studied in the literature assume fixed or static travel times for the networks, an attempt is made to focus on the dynamic routing decisions in response to real-time information. A microscopic traffic simulation model coupled with a link-to-link shortest-path search with turning penalties is suggested and developed to evaluate the potential benefits of the dynamic routing decisions, which considers both updated link travel times and the incident conditions detected. The simulation results are described and discussed. Some interesting issues for future research needs are also recommended. This research will help logistics companies assess the benefits of the routing advisory systems that they use for their day-to-day operations.
Vehicle Dynamics Model for Estimating Maximum Light-Duty Vehicle Acceleration Levels
Authors: Rakha Hesham , Snare Matthew , Dion François
Published: April 2007

A vehicle dynamics model for predicting maximum light-duty vehicle accelerations for use within a microscopic traffic simulation environment is presented and validated. The research also constructs a database of unconstrained vehicle acceleration data for 13 light-duty vehicles and trucks. With the use of the field data, the proposed vehicle dynamics model is validated and compared with a number of state-of-the-art vehicle acceleration models, including the Searle model and the dual-regime, linear decay, and polynomial models. The advantages of the proposed model include its ability to predict vehicle behavior accurately with readily available input parameters and its flexibility in estimating acceleration rates of both large and small vehicles on varied types of terrain.
Multicommodity Kinematic Wave Simulation Model for Network Traffic Flow
Authors: Jin W. L. , Zhang H. M.
Published: April 2007

A multicommodity discrete kinematic wave model that possesses the theoretical rigor and computational efficiency inherent in the kinematic wave theory is proposed for simulating network traffic flow. In this model, fluxes through boundaries and junctions are computed systematically under the supply-demand framework. In addition, traffic is modeled by commodity type so that the effects of geometric characteristics of a road network on traffic dynamics can be captured. Although traffic is not ordered down to the vehicle level as in existing kinematic wave simulation models, the noncompliance with the first-in-first-out property in this model is still of the order of Δ t, the time increment. Hence travel times in the average sense can be defined from cumulative curves. Finally, the evolution of traffic dynamics in a sample road network is shown to demonstrate the stability, numerical convergence, and soundness of the proposed network kinematic wave model.
Some Properties of Flows at Freeway Bottlenecks
Authors: Zhang Lei , Levinson David
Published: April 2007

The capacity of a freeway segment should be measured only when it is an active bottleneck. The properties of flows at active freeway bottlenecks have a bearing on both the definition of capacity and the procedure of capacity analysis. Past studies have examined the flow features at bottlenecks on several freeways in Toronto, Canada, and San Diego, California. This study examined 27 active bottlenecks in the Twin Cities metro area in Minnesota for a 7-week period. The analysis focuses on the properties of prequeue transition flows (PQFs) and queue discharge flows (QDFs) averaged across various time intervals (30-s, daily average, and long-run average). It is found that the proportion by which flows drop after upstream queues form at all studied bottlenecks ranges from 2% to 11%. The 30-s QDFs display high variation and should not be assumed to be constant. The daily average QDFs at each studied bottleneck follow a normal distribution based on two normality tests and visual inspection of the normal probability plot. Results also suggest that the long-run average QDFs [mean of 2,016 passenger cars per lane per hour (pcplph)] and PQFs (mean of 2,124 pcplph) are both normally distributed. The implication of these empirical findings on capacity estimation is also discussed.
Quality-of-Service Perceptions by Rural Freeway Travelers: Exploratory Analysis
Authors: Washburn Scott S. , Ramlackhan Kirby , McLeod Douglas S.
Published: April 2007

In recent years the Transportation Research Board's Highway Capacity and Quality of Service Committee (HCQSC) has debated how performance measures for defining level of service (i.e., service measures) for a facility should be selected. The historical approach has been for the HCQSC to select the measure (or measures) thought most appropriate. However, some committee members have been suggesting that the selection of service measures should be based on research involving the driving public at large and that this research should either directly or indirectly obtain information from drivers and passengers on perceptions of quality and level of service. A preliminary investigation determining the factors that affect traveler-perceived quality of service on rural freeways using in-field surveys of motorists traveling on rural freeways has been conducted. In regard to quality of service, it is becoming more evident that travelers consider multiple factors, and the results from this study support that notion. Specifically, the survey shows that most respondents consider three or more factors important in determining their quality of service on rural freeways. Although density still appears to be a primary factor affecting perceived quality of service, additional factors, such as speed variance and percentage of freeflow speed, seem just as important to travelers. In addition, some nontraffic-performance measures, such as pavement quality and driver etiquette, were found to be important.
INTEGRATION 2.30 Framework for Modeling Lane-Changing Behavior in Weaving Sections
Authors: Rakha Hesham , Zhang Yihua
Published: April 2007

The effectiveness of the INTEGRATION 2.30 model for analysis of weaving sections is validated by a comparison of the lateral and longitudinal distributions of simulated and field-observed traffic volumes categorized by origin-destination pair on nine weaving sections in the Los Angeles, California, area. The results demonstrate a reasonable degree of consistency in the spatial distribution of lane flows between simulated and field-observed traffic volumes within the weaving sections (spatial lane volume error of 250 veh/h or 25%). Furthermore, the spatial distribution of lane changes across the weaving lanes matches field-observed trends. Finally, the study demonstrates how the use of optional lane-bias and lane-changing parameters can enhance the consistency between model results and field data. Overall the study demonstrates the flexibility of the INTEGRATION software for the modeling of weaving sections.
Creative Solutions for Assessing Level of Service Equally Across Modes
Authors: Winters Philip L. , Tucker Lisa E.
Published: April 2007

Transportation professionals base the level of service (LOS) for automobile, bicycle, pedestrian, and transit modes on various criteria, and therefore the LOS is calculated differently for each mode. The current classification schemes make total transportation performance and multimodal trade-off decisions difficult to assess, and the measures do not reflect expectations. The primary objective of this Florida Department of Transportation research project was to identify new approaches for developing an LOS system that planners can use to assess automobile, bicycle, pedestrian, and transit modes of travel equally. Aided by a systematic creative thinking approach, an expert panel identified the perceived values, the feasibility, and the benefits of each alternative approach. The panel also identified the difficulties and cautions associated with each of the alternatives. Furthermore, the expert panel concluded that the fundamental need in developing a method to assess LOS equally across modes would be to correlate the levels for each mode with user perceptions. On the basis of group discussions and in consideration of Maslow's hierarchy of needs, the panel postulated that a hierarchy of transportation user needs would consist of five levels: safety and security (the most basic need), time, societal acceptance, cost, and comfort and convenience (the highest need). The next task in developing a method to assess LOS equally across modes should be the scientific evaluation of the hypothesis of a transportation user hierarchy of needs to determine its validity and effectiveness.
Variations in Queue Discharge Patterns and Their Implications in Analysis of Signalized Intersections
Authors: Lin Feng-Bor , Tseng Pin-Yi , Su Cheng-Wei
Published: April 2007

Saturation flow is traditionally treated as a stabilized maximum rate at which queuing vehicles can be discharged from a lane after the signal changes to green. Traffic engineers in many countries have been using this parameter to estimate the capacities of traffic lanes at signalized intersections. The estimated capacities in turn are used to estimate other performance measures and to classify levels of service. This traditional method of analysis is an efficient way for capacity estimation if the queue discharge rate rises quickly to a steady maximum after onset of the green signal. Actual queue discharge patterns, however, often do not display an easily identifiable steady maximum rate. This characteristic renders the use of saturation flow troublesome and prone to errors that can lead to poor planning and operational decisions. The pitfalls in the current use of saturation flow are examined, and ways of alleviating the problems are suggested.
Issues Related to Federal Funding of Bus Rapid Transit
Authors: Barker William G. , Brosch Gary , Polzin Steven E.
Published: April 2007

Bus rapid transit (BRT) has emerged as a frequent option in the development of the long-range transit plans for urban areas in the United States. This has come about because of the growing number of BRT success stories in the United States and around the world, because of a desire to consider lower-cost investment options at a time of limited resources, and because of encouragement from FTA. The key to the success of BRT is its potential to increase transit service quality and ridership meaningfully at an affordable price. As the BRT concept is evolving, issues in regard to federal funding for BRT investments are critical to localities considering BRT investments. Not surprisingly, there is a growing interest in how best to fund BRT and specifically how best to position BRT with respect to existing federal funding programs and programming processes. A review was conducted of the background context on BRT including the definition and cost history of BRT. There is also a discussion of the current and possible future eligibility for existing and proposed funding programs at the federal level. Three alternative strategies were considered: eliminating the fixed-guideway restrictions of the New Starts Program without turning it into a conventional bus program, expanding the funds available enough under the Bus Capital Program to fund BRT with incentives to encourage true BRT projects, and creating an entirely new BRT funding program. The conclusion addresses issues to be considered as BRT federal funding eligibility is determined.
Fleet Size and Mix Optimization for Paratransit Services
Authors: Fu Liping , Ishkhanov Gary
Published: April 2007

Most paratransit agencies use a mix of different types of vehicles ranging from small sedans to large converted vans as a cost-effective way to meet the diverse travel needs and seating requirements of their clients. Currently, decisions on what types of vehicles and how many vehicles to use are mostly made by service managers on an ad hoc basis without much systematic analysis and optimization. The objective of this research is to address the underlying fleet size and mix problem and to develop a practical procedure that can be used to determine the optimal fleet mix for a given application. A real-life example illustrates the relationship between the performance of a paratransit service system and the size of its service vehicles. A heuristic procedure identifies the optimal fleet mix that maximizes the operating efficiency of a service system. A set of recommendations is offered for future research; the most important is the need to incorporate a life-cycle cost framework into the paratransit service planning process.
Strategic Management at the Pennsylvania Department of Transportation: A Results-Driven Approach
Authors: Poister Theodore H. , Margolis David L. , Zimmerman Douglas E.
Published: April 2007

In 1982, the Pennsylvania Department of Transportation (PennDOT) became one of the first transportation agencies to introduce strategic management as an operating principle. PennDOT's process includes an agency strategic agenda that is developed every 4 years under the guidance of a strategic management committee and is implemented through annual business plans. Strategic plans are used to drive other management and decision-making processes to achieve agency goals and objectives. Four separate administrations representing different political parties have used this process to improve PennDOT's business results and have enhanced the process in each successive iteration. Despite this record of success, a 1998 Baldrige assessment revealed that PennDOT's strategic management process had significant shortcomings—particularly in the area of implementation. A 2-year gap closure effort was initiated in response to these findings; the effort strengthened the overall process and established scorecard targets, linking planning to implementation and facilitating monitoring and review throughout the department. Strengths and opportunities were identified along with recent enhancements made by the current strategic management committee after the change of administration in 2003.
Implementing a Suburban Network of Transit-Oriented Development Centers: Policy Implications
Authors: Swenson Carol J. , Dock Frederick C.
Published: April 2007

Urban design and transportation research conducted as part of the Minneapolis-St. Paul, Minnesota, Transportation and Regional Growth Study are drawn on to make the argument that despite formulaic descriptions of transit-oriented development (TOD), individual centers produce different findings, influenced by local context, location within a region, access to regional transit systems and road networks, and even how land use mixes are organized within a development. It is suggested that the geographic area that is modeled as part of a transportation study should not be uniformly limited to the traditional 1/2-to 1/2-mi radius associated with TOD; rather, boundaries should be responsive to the development context surrounding the center. It is also suggested that local governments debating the merits of a proposed center may need to consider impacts and planning factors beyond their municipal boundaries and that regions encouraging such alternative development patterns may need to provide planning assistance to enable cities to look outside their borders. It is concluded that intergovernmental and interagency planning coordination and cooperation are necessary to develop a regional network of mixed-use centers successfully. Finally, a research agenda is proposed for complementing and expanding existing theoretical and empirical work and thereby improving the reliability and comparability of TOD transportation studies.
Methodology for Multicriteria Decision Making in Highway Asset Management
Authors: Li Zongzhi , Sinha Kumares C.
Published: April 2007

A methodology is proposed for multicriteria decision making involving trade-off analyses between candidate projects as well as project selection and programming in highway asset management under certainty, risk, and uncertainty. A set of system goals in highway asset management structure was first identified, and relative weights of the system goals were determined. Performance indicators under each goal were identified. Benefits achieved under various system goals as a result of implementing a project are typically measured with noncommensurable units; they need to be converted into nondimensional units so that trade-offs between projects can be measured under equal parameters. Where such conversion processes involve certainty and risk, this paper develops systemwide multiattribute utility functions for individual asset management programs to form the basis of trade-off analyses. Because of the limitation of utility theory for situations under uncertainty, an alternative approach based on Shackle's model was introduced, and corresponding functions for project trade-offs were calibrated. The two sets of functions were collectively termed "systemwide trade-off functions" and used to deal with cases under certainty, risk, and uncertainty. A case study was conducted for systemwide highway project selection using information on candidate projects in past state highway programming in Indiana. Case study results were further compared with actual highway programming practice in Indiana to validate the proposed methodology. High matching rates of at least 85% were achieved for decision making under certainty, risk, and uncertainty. The approach could be adopted by other state transportation agencies for asset management practice.
Inequitable Effects of Transportation Policies on Minorities
Authors: Sanchez Thomas W. , Stolz Rich , Ma Jacinta S.
Published: April 2007

Americans are increasingly mobile and ever more reliant on automobiles for meeting their travel needs; this trend developed primarily as a result of transportation policies adopted after World War II that emphasized highway development over public transportation. These and other transportation policies have had inequitable impacts on minority and low-income populations and often restricted their ability to access social and economic opportunities, including job opportunities, education, health care services, and locations such as grocery stores. Transportation policies limit access to opportunities through direct effects, such as inequitable costs, and indirect effects, such as residential segregation. Some indirect effects are caused in part by the combined effects of transportation policies and land use practices. Areas where transportation policies have inequitable impacts are identified. In addition, existing research in the area is briefly examined, and highlighted is the critical need for more research and data collection related to the impact of transportation policies on minority and low-income communities.
Research Implementation and Information Dissemination
Authors: Griffith Andrew , Krugler Paul
Published: April 2007

The Texas Department of Transportation (TxDOT) has a strong and successful research program. One of its key features is an emphasis on ensuring that innovative products developed during research are effectively implemented in the field. Implementation efforts succeed for several reasons: ( a) the involvement of all levels of TxDOT staff in research and implementation, including each of TxDOT's 25 district engineers and technical division directors; ( b) the use of implementation programs specifically designed to bring new products into actual use; ( c) the use of senior-level program coordinators who accept responsibility for a project and champion its implementation; ( d) the use of regularly distributed project summary reports that track a project from inception through development and implementation; ( e) the dissemination of a special annual report that showcases the year's top innovations; and ( f) dedicated funding being secured specifically for implementation projects. In 2002, TxDOT conducted an analysis to determine the value of its research. It focused on the 21 most innovative products implemented in the previous 3-year period and concluded that the operational cost savings derived from the use of these 21 products exceeded the cost of the research program by approximately $268 million—a net return-on-investment ratio of 5:1.
Deployment of Intelligent Transportation Systems in Countries with Developing and Transitional Economies: ITS Toolkit
Authors: Yokota Toshiyuki , Ishida Haruo , Kato Kotaro
Published: April 2007

To provide guidance to countries with developing and transitional economies on strategies for introducing intelligent transportation systems (ITS) and to help with the challenges of surface transportation, the World Bank and Japan's Ministry of Land, Infrastructure, and Transport published the ITS Toolkit. In brief, ITS is the application of information technology (IT)—computers, communications, sensors, databases, and the like—to these challenges. Most ITS applications, however, have arisen in developed countries because of the rapidly falling costs of IT equipment, the prevalence of tried and tested off-the-shelf ITS solutions, and the prevalence of other general-purpose IT infrastructure, such as mobile phone networks, the Internet, and digital road maps, which have allowed new services, or old services provided in a different way, to be acquired with much less outlay. This suggests that as ITS becomes more affordable, the chances to introduce ITS are expanding to countries with developing and transitional economies. Discussed are the emergence of affordable ITS, ITS culture around the world, issues to consider in ITS deployment, and policy recommendations for ITS deployment in countries with developing and transitional economies. A brief overview of the guidance of the ITS Toolkit is also included. The guidance is aimed primarily at policy makers and decision makers in those countries with developing and transitional economies. It strives to provide the background, context, and tools for effective ITS planning and decision making and addresses social, institutional, and legal issues as well as technology.
Parking Guidance System: San Jose, California
Authors: Spencer Mark E. , West James
Published: April 2007

A feasibility analysis and concept plan was recently developed for a parking guidance system (PGS) in downtown San Jose, California. As San Jose continues to grow, real-time parking management is needed to manage the increased demand. A PGS will direct motorists to city and privately owned parking facilities. The system will inform drivers of parking locations and availability with electronic message signs located at key locations on major streets and freeway exit ramps. Having timely and accurate information will allow drivers to make informed decisions about where to park, thus increasing the efficiency of parking facilities. The concept was developed under the direction of the city's Department of Transportation and was finalized in September 2000. With the support of city officials and downtown stakeholders, the development of plans, specifications, and engineering began in late 2000. Funding was set aside for the design and initial implementation of the program. The concept, design, and issues associated with implementation of a PGS are discussed. Following deployment, San Jose's PGS will be one of the largest applications of real-time parking management in North America.
Emergency Evacuation Planning with Microscopic Traffic Simulation
Authors: Jha Mithilesh , Moore Katie , Pashaie Behruz
Published: April 2007

A microscopic simulation model (MITSIMLab) for evaluating emergency evacuation plans was developed for the Los Alamos National Laboratory (LANL). MITSIMLab was used as the microscopic traffic simulator to model traffic operations. The study area consisted of the entire region that includes all technical areas within the LANL and the towns of White Rock and Los Alamos, New Mexico. Evacuation planning is a critical component of overall security planning. The approach adopted presents a laboratory-like setup to evaluate a large range of evacuation scenarios including no evacuation. Five evacuation scenarios are considered in LANL evacuation planning. The scenarios, developed in consultation with the Emergency Management Office of LANL, include full or partial closures of various roads, limited access to some special facilities, and security delays at certain locations. Performance measures for evaluating an evacuation plan include the total time to achieve a complete evacuation, the time needed for a partial evacuation in which the population within certain areas is at risk, and the percentage of the population in affected zones as a function of time.
Traveler Information Provision for Incident Management: Implications for Vehicle Emissions
Authors: Kaysi Isam , Chazbek Chadi , El-Fadel Mutassem
Published: April 2007

The potential of intelligent transportation systems (ITS) in alleviating nonrecurring traffic congestion was assessed, and then the resulting implications for vehicle-induced emissions in a congested city in a developing country were estimated. This work provides a blueprint for future studies on both the evaluation of ITS deployment through dynamic traffic modeling and the assessment of resulting changes in travel times and emissions. The Greater Beirut, Lebanon, area road network was used as the test bed for evaluating strategies for incident management, which was the selected ITS application for this study. A series of simulation scenarios was conducted with dynamic traffic-simulation-assignment methodology, and resulting emissions were estimated with an emission-factor model. These scenarios were used to evaluate the effect of different ITS deployment parameters—such as type of information provision (pretrip and in-vehicle) and driver compliance—on network performance and resulting emissions. Network performance measures such as travel and stop times were developed, and corresponding vehicle emissions were estimated with carbon monoxide, nitrogen oxides, and total organic carbon as indicators for each scenario.