bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of a Scheduling Model for Car Tourists’ 1-Day Tours
Authors: Fujiwara Akimasa , Zhang Junyi
Published: May 2018

Focusing on car tourists’ 1-day tours, a new scheduling model combines a nested paired combinatorial logit (NPCL) type of destination and route choice model and a time allocation (TA) model. The NPCL model, developed previously from the generalized extreme value family of discrete choice models to represent the similarity between pairs of alternatives in the same choice nest as well as the influence of inclusive value, indicates destination choice in the bottom level and route choice in the top level. The TA model applies Becker's theory to determine the time allocated to each touring site. Utility of destination choice is influenced by the time spent at each site. Different route choices result in a level of service for the road network that varies hourly, varying available time used in the TA model. The TA model endogenously incorporates the influence of hourly variance in level of service at the site of interest, which is affected by the allocated time. An iteration estimation procedure is proposed to estimate the parameters consistently in both models. Finally, revealed preference tourist travel survey data collected in a tourist attraction region near the Sea of Japan indicate that the proposed scheduling model is effective in representing car tourists’ scheduling behavior for 1-day tours.
Simulation Estimation of Mixed Discrete Choice Models with the Use of Randomized Quasi–Monte Carlo Sequences
Authors: Sivakumar Aruna , Bhat Chandra R. , Ökten Giray
Published: May 2018

The overall performance of the quasi–Monte Carlo (QMC) sequences proposed by Halton and Faure, as well as their scrambled versions, are numerically compared against each other and against the Latin hypercube sampling sequence in the context of the simulated likelihood estimation of a mixed multinomial logit model of choice. In addition, the efficiency of the QMC sequences generated with and without scrambling is compared across observations, and the performance of the Box–Muller and inverse normal transform procedures is tested. Numerical experiments were performed in five dimensions with 25, 125, and 625 draws and in 10 dimensions with 100 draws. Results indicate that the Faure sequence consistently outperforms the Halton sequence and that the scrambled versions of the Faure sequence perform best overall.
Escorting Children to School
Authors: Vovsha Peter , Petersen Eric
Published: May 2018

An important aspect of intrahousehold interactions–-joint travel arrangements that arise when adult household members escort children to school–-is investigated. Previously published research on intrahousehold interactions have focused mostly on time allocation or episode generation between individual and joint activities and have largely been limited to interactions between household heads. Insights into the less-explored aspect of intrahousehold interactions between adults and children in the household are provided. Children are explicitly considered active agents in the intrahousehold decision making, and the interaction itself takes the form of a joint travel arrangement rather than a shared activity. A statistical analysis indicates the importance of this segment of intrahousehold interactions in the overall system of household activity and travel. A choice model, which is formulated and estimated, relates the probability of various types of ridesharing and escorting to the person, household, and zonal variables. The developed model is designed for possible inclusion in the regional travel model system being developed for the Atlanta (Georgia) Regional Commission.
Stops for Cops
Authors: Rizzo Matthew , Shi Qian , Dawson Jeffrey D. , Anderson Steven W. , Kellison Ida , Pietras Thomas
Published: May 2018

Response to an emergency vehicle requires detection and recognition of an object in peripheral vision, situation recognition, and a rapid response to execute a safety maneuver to decrease the potential for crashing into the vehicle or striking people situated near it. To investigate situation awareness and response to a roadway emergency in at-risk elderly drivers, 149 licensed older drivers were tested with a battery of visual and cognitive tests and in a driving simulator scenario in which drivers encountered a police car on the shoulder of the road. Forty-eight drivers (mean age of 73.5) had cognitive impairments caused by mild to moderate Alzheimer's disease, and 101 (mean age of 69.3 years) were neurologically normal. Results showed that compared with controls, drivers with Alzheimer's reacted more slowly (P = 0.0008)—with abrupt decelerations resulting—or failed to steer clear of the police car (P = 0.0036). Several older drivers stopped in the middle of the road. Poorer scores on neuropsychological tests of perception, attention, memory, and executive function predicted slower first reactions and increased the risk of inappropriate and potentially unsafe reactions. These results provide evidence that cognitive errors leading to unsafe driver behaviors can be tested safely in a simulator. The findings suggest that there is decreased situation awareness or poor executive control over response implementation in older drivers with cognitive decline, possibly at the level of selecting one of several possible learned evasive motor actions.
Driver Identification of Landmarks and Traffic Signs after a Stroke
Authors: Uc Ergun Y. , Rizzo Matthew , Anderson Steven W. , Shi Qian , Dawson Jeffrey D.
Published: May 2018

A study was done to assess the ability for visual search and recognition of roadside targets and safety errors during a landmark and traffic sign identification task in drivers with stroke, that is, drivers who have had a stroke. Visual search for roadside targets during automobile driving can compete for a driver's cognitive resources and may impair driving, especially in drivers with cognitive impairment caused by stroke. Thirty-two drivers with stroke and 137 neurologically normal older adults underwent a battery of visual, cognitive, and motor tests and were asked to report sightings of specific landmarks and traffic signs along a segment of an experimental drive. The drivers with stroke identified significantly fewer landmarks and traffic signs and showed a tendency to make more at-fault safety errors during the task than did control subjects. Roadside target identification performance and safety errors were predicted by scores on standardized tests of visual, cognitive, and motor function. Drivers with stroke are impaired in a task of visual search and recognition of roadside targets whose demands on visual perception, attention, executive functions, and memory probably increased the cognitive load and worsened their driving safety.
Investigation of Time into Red for Red Light–Related Crashes
Authors: Zimmerman Karl , Bonneson James A.
Published: May 2018

This paper describes a research effort to determine the time into red of 63 red light–related crashes. From these 63 crashes, the relationship of time into red and the red light–related crash type is explored, as are relationships to other factors. From the red light–related crashes investigated, it was found that red light–related crash type was related to time into red. Other factors were not found to be related to time into red, although the sample size and selection method prevented any definitive findings. A brief discussion of the possible safety effectiveness of the all-red interval is also included. The time into red of red light–related crashes is related to the time into red of red light violations, so a characterization of red light violations and crashes is provided, along with suggested red light violation countermeasure classifications for each type of red light violation.
Implementing Red Light Camera Programs
Authors: Council Forrest M. , Persaud Bhagwant , Lyon Craig , Eccles Kimberly , Griffith Mike , Zaloshnja Eduard , Miller Ted
Published: May 2018

Red light camera (RLC) systems are believed to decrease the right-angle crashes that they are targeting but to have the undesirable side effect of increasing rear-end crashes. This belief was confirmed in a before–after study of 132 RLC installations in seven U.S. jurisdictions, as reported in a companion paper. In that research, the extent to which the increase in rear-end crashes negates the benefits for right-angle crashes was unclear, given the perceptions of severity differences in the two crash types. This paper reports on an examination of the changes in crash costs, based on a consideration of rear-end and right-angle unit crash costs for various severity levels, to establish the aggregate effects of the RLC programs evaluated. Part of the project derived the required unit costs by using information from national U.S. databases. The overall results show a modest to moderate economic benefit of between $28,000 and $50,000 per treated site year, depending on assumptions made. The ability to aggregate economic costs across crash types and severity created the opportunity to try to isolate program implementation factors and intersection characteristics that would favor the installation of RLC systems by using the aggregate economic benefit at each RLC site as the outcome variable. This investigation found, for example, that the greatest economic benefits are associated with the highest total entering annual average daily traffic, the largest ratios of right-angle to rear-end crashes, and the presence of protected left-turn phases.
Measuring Neighborhood Traffic Safety Benefits by Using Real-Time Driver Feedback Technology
Authors: Chang Kevin N. , Nolan Matthew , Nihan Nancy L.
Published: May 2018

Local jurisdictions frequently respond to public concerns about speeding on neighborhood streets. When a speed study confirms that a significant percentage of vehicles are exceeding the posted speed limit, a traffic engineer carefully reviews the conditions to determine if additional safety measures need to be implemented. Preserving roadway safety for the motorized and the nonmotorized public alike who share the roadway is essential. Each jurisdiction is likely to use any number of solutions from its traffic safety toolbox. Additional signing, mobile radar speed display units, neighborhood speed watch programs, or targeted police enforcement may help discourage drivers from traveling at unacceptable speeds. Physical devices, such as traffic circles, speed humps, and chicanes, can also be considered but will affect emergency vehicles by increasing their response times. To balance increased driver awareness of travel speeds with vehicle accessibility, the King County Department of Transportation in Washington State installed four radar speed signs along 108th Avenue NE between NE 124th Street and Juanita-Woodinville Way NE. These radar speed signs, installed directly below the black-and-white regulatory speed limit signs, alerted each driver by indicating travel speed. To evaluate the effectiveness of these signs, speed studies were conducted before, during, and after installation. The results from these studies are presented, installation and maintenance of this device are discussed, and conclusions are drawn about whether these signs have been successful in calming neighborhood traffic.
Safety Reviews of Existing Roads
Authors: Montella Alfonso
Published: May 2018

Safety reviews of existing roads are becoming an accepted practice in many agencies around the world. These reviews can be highly cost-effective, but the subjective nature of the process can give rise to inconsistencies that limit their effectiveness. To address this issue, a technique to support safety reviews to quantify the safety gains that could be achieved by addressing the problems identified in the review process is presented. The approach is based on known accident relationships. A systematic process to determine which road features should be investigated and how each feature should be evaluated during the review is described. The procedure addresses rural two-lane highways at nonintersections. From the process, a potential for a safety improvement index (PFI) was calculated. Validation of the procedure was carried out by a comparison of the PFI values with the expected collision frequency. PFI was assessed in 406 km of rural two-lane rolling highways in Italy. Collision frequency was determined by application of a collision prediction model, calibrated in the study network, and was refined by application of the empirical Bayes (EB) technique. Correlation between EB safety estimates and PFI values is highly significant, with 93% of the variation in the estimated number of accidents explained by the PFI value. Because of the validation and quantitative nature of the PFI, the procedure can be used to support safety reviews and decision making.
Integrating Safety into the Transportation Planning Process
Authors: Ravanbakht Camelia , Belfield Samuel S. , Nichols Keith M.
Published: May 2018

The Transportation Equity Act for the 21st Century requires metropolitan planning organizations (MPOs) to incorporate safety and security into the transportation planning process as one of the seven planning factors. The Hampton Roads Planning District Commission (HRPDC) is the designated MPO for Southeastern Virginia. In 2001, as part of its congestion management system (CMS) program, the HRPDC staff initiated a comprehensive regional safety study, which included collecting comprehensive crash data and creating a regional database for 151 Interstate segments and 13,000 intersections. The crash severity method was used to analyze, rank, and determine the top high-crash locations for Interstate segments as well as the CMS intersections. This regional safety study was designed to help local communities understand safety-related problems and issues. Congestion, failure to yield the right-of-way, following too closely, driver inattention, and disregarding traffic signals were found to be the main causes of traffic crashes in Hampton Roads between 1998 and 2000. Rear-ends and right angles were the predominant crash types during the period. The study analyzed and recommended a series of safety-related countermeasures and solutions for the top-10 high-crash locations throughout the region. Some common countermeasures that were recommended were adding roadway capacity, adding turn lanes at intersections, improving signal timing, improving signage, increasing enforcement, and providing additional driver education.
Rural School Vehicle Routing Problem
Authors: Ripplinger David
Published: May 2018

The school bus routing problem traditionally has been defined in an urban context. However, because of the unique attributes of the problem in rural areas, traditional heuristic methods for solving the problem may produce impractical results. In many cases, these characteristics also provide the opportunity to investigate what size and mix of vehicles, whether large or small buses, conforming vans, or other modes, are most efficient. In addition, these vehicles may be further differentiated by the presence of equipment for transporting students with special needs. To address this situation, a mathematical model of the problem was constructed and a new heuristic was developed. This heuristic consists of two parts: constructing the initial route and then improving it by using a fixed tenure tabu search algorithm. This rural routing heuristic, in addition to several existing ones, is then applied to a randomly generated school district with rural characteristics. For the relevant measure, a function of student ride time, the new heuristic provides a set of routes superior to those produced by existing methods. Because ride times produced by the new heuristic are lower than those for routes generated by existing methods, the likelihood of injury to students may decrease. Also, with the cost of operation for each route calculated in dollars, a comparison of solutions in financial, as well as temporal, terms is possible.
Modeling and Performance Assessment of Contraflow Evacuation Termination Points
Authors: Lim Erick , Wolshon Brian
Published: May 2018

About 20 hurricane evacuation contraflow segments are planned for use in the United States. When activated, these routes will serve as lifelines for people fleeing the potential destruction of approaching storms. The termination points of these segments are critical because they move traffic from the reverse-flowing lane into the normal flow direction. They are also thought to affect the overall effectiveness of the sections significantly because they can regulate the amount of volume that exits the section. The research effort described in this paper was undertaken to assess and compare the operational characteristics of contraflow evacuation termination point designs that would be used under threat from catastrophic storms. Among the developments of the research was an approach and set of assumptions for using CORSIM to model contraflowing freeway traffic under evacuation conditions. These models were used to assess and rank the planned termination designs comparatively and to identify the factors that made some designs more effective than others, including the effect of reducing traffic volumes before the termination. The quantification of the operations revealed several important concepts relative to the use of contraflow evacuation segments. First, it is advantageous to maintain all lanes through the termination point with split rather than merge designs. Also, it is advantageous to reduce the volume entering the termination point by maintaining exit points along the route. The study suggests that merge zones located after exits, instead of before them, and the use of channelization or separation devices well in advance of forced maneuvers can enhance the quality of the flow through the termination vicinity.
Simulation-Based Emergency Evacuation System for Ocean City, Maryland, during Hurricanes
Authors: Zou Nan , Yeh Shu-Ta , Chang Gang-Len , Marquess Alvin , Zezeski Michael
Published: May 2018

This paper presents a simulation-based system for Ocean City, Maryland, evacuation during hurricanes. The proposed model features integration of optimization and simulation that allows potential users to revise the optimized plan for both planning and real-time operations. Since it is difficult to capture all network operational constraints and driver responses fully with mathematical formulations, six evacuation plans for Ocean City were investigated. Each was optimized initially with the optimization module and then revised on the basis of the results of simulation evaluation. To address potential incidents during the evacuation, the study presents a real-time operation plan with a developed system that allows the responsible operators to concurrently evaluate all candidate responsive strategies and to track the performance over time of the implemented strategy.
Online Dispatching and Routing Model for Emergency Vehicles with Area Coverage Constraints
Authors: Yang Saini , Hamedi Masoud , Haghani Ali
Published: May 2018

Response time plays a crucial role in reducing the loss of assets and lives caused by emergencies. Good dispatch strategies for emergency response vehicles result in more efficient service, and route guidance can help reduce vehicles’ travel times. Because of a limited number and type of emergency response vehicles at each station, service area gaps will be created: they cannot be properly covered by the remaining emergency response vehicles when some vehicles are dispatched. Future emergency calls in these areas may experience longer response times than usual. In this paper, an optimization model is developed that, given real-time traffic information, can assist dispatchers of emergency response vehicle in assigning multiple emergency response vehicles to incidents and in determining the routes that avoid congestion spots in the transportation networks. This model accounts for the service area coverage concerns (when several vehicles are busy) by relocation and redistribution of the remaining vehicles among stations. The results show that coordination of different types of vehicles, relocation of vehicles for better area coverage, and use of a time-dependent shortest path algorithm in this model significantly improve the performance of the emergency response system.
Improved Path Flow Estimator for Origin–Destination Trip Tables
Authors: Chootinan Piya , Chen Anthony , Recker Will
Published: May 2018

Path flow estimator (PFE) is a one-stage network observer that can estimate path flows and path travel times from traffic counts in a transportation network. Because a unique set of path flows is readily available from the PFE, a trip table can be estimated by simply adding up flows on all the paths connecting individual origin–destination (O-D) pairs. In this paper, the effects of the number and locations of traffic counts on the quality of the O-D trip table estimated by PFE are examined. The set-covering model, studied in the location theory, is applied to determine the minimum number of traffic counts and their corresponding locations required to observe the total demand of the study network. Next, the effects of the error bounds used in PFE to handle the inconsistency problem of traffic counts are examined, and a heuristic using the Lagrange multipliers to facilitate the adjustment of such error bounds is provided. Numerical results show that PFE can correctly estimate the total demand of the study area if a sufficient number of traffic counts collected at appropriate locations is provided. The results further indicate that improper specification of the error bounds could lead to biased estimation of total demand utilizing the network.
Commodity-Based Truck Origin–Destination Matrix Estimation Using Input–Output Data and Genetic Algorithms
Authors: Al-Battaineh Omar , Kaysi Isam A.
Published: May 2018

A commodity-based model to estimate a truck origin–destination (O-D) matrix is presented. The model takes advantage of the genetic algorithm global search method to find the best O-D matrix that when assigned to the network gives the minimum deviation between observed and estimated data. The model is flexible with respect to the type of data used in estimating the O-D matrix; however, the case study presented in this paper takes into consideration only two sets of information: commodity flow on specific links and column and row sums of the O-D matrix. Flows are treated as commodity dollar value; therefore, the estimated O-D matrix entries consist of the value of the commodity shipped by truck from the origin zone to the destination zone. The method is composed of two submodels. The first submodel, the trip generation model, uses input–output data with employment and population data to estimate the zonal level of commodity attraction and production. The second submodel, the genetic algorithm model, searches globally for the optimum O-D matrix. The model and its application to a case study of a region in Ontario, Canada, are presented. Directions for future research are provided.
Optimal Toll Design Problem in Dynamic Traffic Networks with Joint Route and Departure Time Choice
Authors: Joksimovic Dusica , Bliemer Michiel C. J. , Bovy Piet H. L.
Published: May 2018

Road pricing is one of the market-based traffic control measures that can influence travel behavior to alleviate congestion on roads. This paper addresses the effects of uniform (constant, fixed) and time-varying (step) tolls on the travel behavior of users on the road network. The problem of determining optimal prices in a dynamic traffic network is considered by applying second-best tolling scenarios imposing tolls only to a subset of links on the network and considering elastic demand. The optimal toll design problem is formulated as a bilevel optimization problem with the road authority (on the upper level) setting the tolls and the travelers (on the lower level) who respond by changing their travel decisions (route and departure time choice). To formulate the optimal toll design problem, the so-called mathematical program with equilibrium constraints (MPEC) formulation was used, considering the dynamic nature of traffic flows on the one hand and dynamic pricing on the other. Until now, the MPEC formulation has been applied in static cases only. The model structure comprises three interrelated levels: (a) dynamic network loading, (b) route choice and departure time choice, and (c) road pricing level. For solving the optimal toll design problem in dynamic networks, a simple search algorithm is used to determine the optimal toll pattern leading to optimization of the objective function of the road authority subject to dynamic traffic assignment constraints. Nevertheless, uniform and time-varying pricing is analyzed, and a small hypothetical network is considered.
Modeling Traffic Flow Operation in Multilane and Multiclass Urban Networks
Authors: Ngoduy D. , Hoogendoorn S. P. , van Lint J. W. C.
Published: May 2018

The traffic control task in heterogeneous multilane motorways and urban networks is complicated because it concerns multiple objectives and multiple target groups (user classes). Furthermore, it is characterized by large differences in driving behaviors between user classes and network types. The latter are caused by the interaction between user classes, the interplay between control measures, and the interaction between different parts of the networks. This complexity requires a model-based approach for achieving better understanding of the complicated process at hand and for the subsequent efficient control of these processes, for example, by applying model-based optimal controls. However, the contemporary macroscopic traffic flow models for urban networks are deficient in that they fail to deal adequately with heterogeneous traffic on multilane links. The aim of this paper is to devise a much more elaborate macroscopic traffic flow model, focusing on urban networks, to be able to cope with the complex control task and its application. The model proposed here is then implemented in the urban part of a computer-based network model, HELENA.
Comparison of System- and User-Optimal Stochastic Dynamic Network Design Models Using Monte Carlo Bounding Techniques
Authors: Karoonsoontawong Ampol , Waller S. Travis
Published: May 2018

This paper compares the continuous network design problem formulations using system-optimal (SO) and user-optimal (UO) dynamic traffic assignment when the following independent stochastic parameters with known discrete probability distributions are considered: time-dependent origin–destination demands, time-varying saturation flow rates and jam density, and network improvement unit costs. These models propagate traffic according to Daganzo's cell transmission model. Two Monte Carlo bounding techniques, common random numbers (CRN) and independent random numbers (IRN) strategies, are used to solve the stochastic models. The results show that the CRN strategy outperforms IRN on a simple test network resembling a freeway corridor. The network size is sacrificed to gain higher confidence probabilistic behavior and to understand intuitively the effects of different network improvement policies. Although the findings may not necessarily be generalized, they provide interesting and insightful information. First, the SO and UO models allocate investment differently for certain budgets, and the stochastic models may lead to an erroneous solution (i.e., a bottleneck) for some budgets. Subsequently, the results of three comparison cases are discussed: (a) for the SO models, it should be more valuable to solve the stochastic than the deterministic models, but it is not always the case for the UO models; (b) the SO models appear more desirable than the UO models for single-level analysis; and (c) it should be more valuable to solve the stochastic model accounting for more randomness.
Robust Model for Estimating Freeway Dynamic Origin–Destination Matrix
Authors: Lin Pei-Wei , Chang Gang-Len
Published: May 2018

This study presents a robust model for estimating the dynamic freeway origin–destination matrix with a measurable time series of ramp and mainline flows. The proposed model captures the speed variance among vehicles having the same departure time, origin, and destination with an embedded travel time distribution function that results in a substantial reduction in model parameters. With the developed solution algorithm, the proposed model offers the potential use in a network of realistic size such as the I-95 freeway corridor between the Maryland I-695 and I-495 beltways. Extensive numerical analyses with respect to the sensitivity of both input measurement errors and the selection of initial parameters have revealed that the proposed model is sufficiently robust for real-world applications.
Microsimulation of Flexible Transit System Designs in Realistic Urban Networks
Authors: Cortés Cristián E. , Pagès Laia , Jayakrishnan R.
Published: May 2018

The use of microsimulation is not prevalent in modeling transit systems. The software available is rarely capable of modeling transit systems that route vehicles in real time or systems that adjust to the level of demand. It is not straightforward to model a transit system with the available simulation packages, especially when the transit scheme is not “standard.” Even the simulation of basic schemes such as a streetcar system or a paratransit service is not an option in existing simulation software. A cursory study would reveal that simulation of any vehicle class other than personal automobiles is always developed as an afterthought in the existing large-scale microsimulation packages. In most cases, simulation developers have done only a superficial addition of transit simulation on top of detailed simulation of automobiles and control mechanisms on freeways and arterials. A microsimulation framework has been developed for a general transit system. Concrete applications of such a framework have been developed and are presented in this paper. Two different transit systems are modeled using the same general framework to show the flexibility of the simulation scheme: a bus rapid transit system and a large-scale real-time routed transit design. The intent is to describe the flexibility that can be brought into a properly designed microscopic simulation platform to model innovative transit system designs, especially in larger urban networks. A simulation scenario is presented in which both transit systems function. The details of both simulations are described along with the problems encountered, and ways to solve them are exposed.
Combinatorial Bid Generation Problem for Transportation Service Procurement
Authors: Wang Xiubin , Xia Mu
Published: May 2018

In combinatorial auctions, solving the bid generation problem (BGP) for bidders is critical to achieving efficiency. However, in the recent surge of combinatorial auction research, little attention has been paid to the BGP. In this paper, the BGP faced by transportation service providers is studied. First, the bidder's optimality criterion of a combinatorial bid is clarified, and then the focus is on the bundling method when an OR bid language is used. Through examples, bundles generated by solving the optimal truck routing problem were examined, and it was found that the resulting bid might not be optimal. This heuristic is compared with a simple nearest insertion method. The simulation result shows that whereas the former outperforms the latter in most cases, many times the latter outperforms the former by 5% to 8%.
Algorithm for Equilibrium Transit Assignment Problem
Authors: Babazadeh Abbas , Aashtiani Hedayat Z.
Published: May 2018

Transit assignment is an important problem in the literature of transportation. Almost all competitive algorithms in this area are strategy based. For uncongested transit networks, the problem may be formulated into an optimization problem for which good solution algorithms exist. A variational inequality formulation of the problem with several solution methods is also presented in the literature for congested networks. This paper is devoted to solving a transit assignment problem based on complementarity formulation using path flows. The solution algorithm exploits the three concepts of decomposition, path generation, and linearization. The procedure has been applied on a large-scale real-case transit network under fixed travel times as well as flow-dependent dwell times. Computational experiments show rapid convergence of the algorithm. Moreover, for the limited experiments performed, the computational time for the flow-dependent problem is only about twice that of the case for the fixed travel times, without an appreciable excess memory requirement.
Travel Behavior and Transportation Needs of People with Disabilities
Authors: O'Neill Yvette , O'Mahony Margaret
Published: May 2018

Arguments defending the poor attention given to those with disabilities in regard to equal opportunities for transportation options tend to center on the high cost of providing or improving facilities. This paper examines the current quality of service on a variety of modes and mode ancillaries, such as stations and stops, as determined by individuals with disabilities. That section is followed by an examination of the measures to improve the quality of service that those with disabilities require. The evaluations are done with four types of disability groups; although the samples of individuals involved are small, the findings are incisive and clear. The improvement measures discussed fall into two categories: those that are costly and those that are more a matter of consideration being given by transportation operators. For example, timetables could be located at a lower level at bus stops to facilitate wheelchair users and stops could be announced as buses approach them. It would appear that in many cases low-cost solutions could be considered marginal changes to work practices or decision making, but the impact they could have on quality of service indicators for those with disabilities, such as accessibility, would be considerable.
Estimating Trip Generation of Elderly and Disabled People
Authors: Schmöcker Jan-Dirk , Quddus Mohammed A. , Noland Robert B. , Bell Michael G. H.
Published: May 2018

The aging of populations has implications for trip-making behavior and the demand for special transport services. The London Area Travel Survey 2001 is analyzed to establish the trip-making characteristics of elderly and disabled people. Ordinal probit models are fitted for all trips and for trips by four purposes (work, shopping, personal business, and recreational), with daily trip frequency as the latent variable. A log-linear model is used to analyze trip length. A distinction must be made between young disabled, younger elderly, and older elderly people. Retired people initially tend to make more trips, but as they become older and disabilities intervene, trip making tails off. Household structure, income, car ownership, possession of a driver's license, difficulty walking, and other disabilities are found to affect trip frequency and length to a greater or lesser extent.
Extending Older Drivers’ Access to Freeways with Intelligent Transportation System Technologies
Authors: Kihl Mary
Published: May 2018

The vanguard of the baby boom generation is approaching retirement age. They received their driver's licenses at the age of 16 at a time when freeways were reshaping urban land patterns. For those living in suburbs and the urban edge, freeway driving is a way of life. Nevertheless, as these drivers age, they too will experience changes in visual acuity and a reduction in their ability to respond quickly to changes in road conditions. Many studies document problems that older drivers face on city streets. The current study funded by the Arizona Department of Transportation and FHWA suggests that freeway driving might be less taxing for some. The study explores the possibility that intelligent transportation system (ITS) devices–-including variable message signs; portable, changeable message signs; and ramp meters–-may respond to older drivers’ challenges with freeway driving. Eleven focus groups held with diverse groups of freeway drivers from 65 to 80 years of age in 2003–2004 focused on these ITS devices and suggested minor changes in application that would enhance their value. Drivers said that fixed variable message signs with a positive contrast caught their attention and were easier to read than standard signs. They urged their use for short simple messages centered on the signs. Portable signs attracted attention, but they were subject to glare and were difficult to read at the roadside, particularly those with multiple phases. Ramp meters were enthusiastically endorsed especially when combined with acceleration lanes. A parallel study using Arizona accident data provided some statistical evidence to support positive views of ramp meters.
Access to Health Care and Nonemergency Medical Transportation
Authors: Wallace Richard , Hughes-Cromwick Paul , Mull Hillary , Khasnabis Snehamay
Published: May 2018

Although lack of access to nonemergency medical transportation (NEMT) is a barrier to health care, national transportation and health care surveys have not comprehensively addressed that link. Nationally representative studies have not investigated the magnitude of the access problem or the characteristics of the population that experiences access problems. The current study, relying primarily on national health care studies, seeks to address both of those shortcomings. Results indicate that about 3.6 million Americans do not obtain medical care because of a lack of transportation in a given year. On average, they are disproportionately female, poorer, and older; have less education; and are more likely to be members of a minority group than those who obtain care. Although such adults are spread across urban and rural areas much like the general population, children lacking transportation are more concentrated in urban areas. In addition, these 3.6 million experience multiple conditions at a much higher rate than do their peers. Many conditions that they face, however, can be managed if appropriate care is made available. For some conditions, this care is cost-effective and results in health care cost savings that outweigh added transportation costs. Thus, it is found that great opportunity exists to achieve net societal benefits and to improve the quality of life of this population by increasing its access to NEMT. Furthermore, modifications to national health care and transportation data sets are recommended to allow more direct assessment of this problem.
Gender-Based Analysis of Work Trip Mode Choice of Commuters in Suburban Montreal, Canada, with Stated Preference Data
Authors: Patterson Zachary , Ewing Gordon , Haider Murtaza
Published: May 2018

Transportation literature suggests that men and women differ in their commuting patterns and in their propensity to switch between travel options. In North America, it is expected that women will have an increasing impact on travel demand. As such, differences in female responses to travel demand management strategies are likely to become increasingly important as governments try to curtail travel demand. This paper uses a 1994 stated preference survey of suburban commuters in Montreal, Canada, to determine whether there is evidence for differences between men and women in the factors that affect work trip choices, to quantify those differences, and to suggest what the differences imply for travel demand management in the future in Montreal. The main conclusions of this paper are as follows. First, women and men should be modeled separately for work trip mode choice. Second, three main differences appear from the econometric models: women are less likely to choose public transit than men; women are more likely to choose to rideshare; and women are less time-sensitive in regard to commuting than men are.
Highway Construction Impacts on Wyoming Businesses
Authors: Young Rhonda Kae , Wolffing Chris , Tomasini Michael
Published: May 2018

Highway construction projects can affect motorists and businesses in many ways. Even though construction projects are temporary situations, many businesses worry about the level of impact during construction and the length and magnitude of the recovery period. Highway construction may cause a temporary loss of customers, revenue, and property value as well as create noise and air pollution and other problems. Currently, there is little information that quantifies the estimated business impacts, particularly for rural areas such as Wyoming. This study investigated the business-related effects of highway construction projects in Wyoming and provided managers at the Wyoming Department of Transportation with case studies and impact estimates to better address business owners’ concerns. The study also compared the businesses’ perceptions of what happened to their sales during and after construction with the actual impact on the businesses’ sales for the same time period. Perceived impact data were collected through surveys sent to businesses in the 12 case study projects across Wyoming, and Wyoming Department of Revenue tax data were used to examine the actual estimated sales data before, during, and after construction. In addition to sales revenue data, traffic volumes and right-of-way purchase information were compared with the business owners’ perceptions. The result of the study was the quantification of actual impacts as well as an analysis of the difference between the actual and perceived impacts.
Strategic Innovations in North American Railroad Management
Authors: Natarajan Balu , Duncan Chandler , Simpson David
Published: May 2018

Although the railroad industry is often regarded as a declining industry with a decreasing modal share of the nation's freight movement, innovations in railroad management are changing the way rail carriers operate and are leading to operational efficiencies for the rail mode. The formation of strategic alliances is transforming the way North American railroads do business and increasing the hope of creating new opportunities for rail as an economically viable and technologically sophisticated element of North America's surface freight transportation network. This conceptual paper examines the pressures and challenges driving the alliance trend of North American railroads from the standpoint of different competitive arrangements in the context of recent strategic management literature. The competitive dimensions and outcomes of recent railroad alliances are analyzed from a business perspective. The paper concludes with insights about the implications of the emerging alliance paradigm not only for railroad management but also for intermodal freight planning and policy in the new millennium.
Collaboration
Authors: Meyer Michael D. , Campbell Sarah , Leach Dennis , Coogan Matt
Published: May 2018

Delivering transportation services and programs that meet the needs of the public often requires the cooperation of numerous organizations and groups. This paper presents the results of a transit cooperative research project that examined collaborative efforts in the transportation sector. Concepts of collaboration as practiced in several transportation contexts are examined. The paper defines collaboration, describes characteristics that are necessary for success, and illustrates the evolution of collaborative efforts from initial efforts at simple coordination to more complex organizational relationships. Questions are provided for those interested in assessing the health of a collaboration at any particular phase of development.
Emerging Performance Measurement Responses to Changing Political Pressures at State Departments of Transportation
Authors: Bremmer Daniela , Cotton Keith C. , Hamilton Brooke
Published: May 2018

Performance measurement is an evolving practice. All state departments of transportation (DOTs) have used some aspect of performance measurement for analyzing system uses and conditions as part of the engineering and planning disciplines. Yet the business management process and accountability aspects of the performance measurement field have emerged in the transportation industry just in the past decade. State DOTs operate under heightened political pressures, and accountability mandates drive change in performance measurement practices. This paper illuminates important trends that drive the evolution of the field and that need greater attention in research. The emerging purposes and needs for performance measurement and performance management have substantial implications for practitioners and managers. The paper first describes the research purpose and method and presents a generational model for conceptualizing the stages in performance measurement development in transportation agencies. Next, the major pressures that drive performance measurement development are noted, and the most pertinent responses uncovered by this research are summarized. The paper concludes with recommendations for advancing the field and opportunities for further research. This report does not critique specific practices or judge state capabilities. Its intention is to describe emerging trends and needs driving the changing practice of performance measurement at state DOTs by using illustrative examples to help practitioners understand the state of the field and prepare for potential challenges ahead.
Risk-Based Life-Cycle Cost Analysis of Privatized Infrastructure
Authors: Osman Hesham
Published: May 2018

One main shortcoming in the use of life-cycle cost analysis (LCCA) for analyzing long-term infrastructure projects is the uncertainty in the value of the LCCA parameters. Probabilistic LCCA incorporates these elements of uncertainty by assigning probabilistic values to cost and performance parameters. Studies that have performed probabilistic LCCA in the infrastructure domain propose a probability-based framework for alternative comparison. Although such frameworks convey a wealth of probabilistic information, they are not well suited to decision making. This study proposes a risk-based framework that is similar to techniques used in portfolio risk management. To illustrate the use of such a framework, a Monte Carlo simulation is used to perform probabilistic LCCA for a highway project. Two highway investment opportunities with varying risks and returns are analyzed. The decision framework is used to compare the simulation results with some common investment opportunities in the market. This framework enables private-sector investors to assess the relative risks and returns of alternative infrastructure projects. The fact that similar frameworks are used in the financial investment domain makes this approach suitable for the economic analysis of privatized infrastructure.