bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of Effects of Ramp Metering on Merging Operations
Authors: Zheng Pengjun , McDonald Mike
Published: January 2008

Merging on motorways represents one of the most difficult and dynamic maneuvers of all driving subtasks. Merging operations at uncontrolled ramp junctions have been extensively investigated. With the rapid implementation of ramp metering techniques, many junctions are now operated under ramp metering control. Little research has been done to investigate the possible effects of ramp metering on the merging operation. The research described in this paper focuses on the comparisons of merging operations under both metered and unmetered scenarios. Time series data of the merging process were collected with the Transportation Research Group instrumented vehicle and video cameras at a tapered motorway merge site. The data included accurate vehicle speed measured by laser speedometer, leading and following headway measured by radar, and driver's eye movement derived from an in-car camera. Following a comprehensive analysis of the data, it was found that merging operations under ramp control could be significantly different from free merging. Merging maneuvers may become more difficult as a result of ramp control. The equity implications of such effects are discussed. It is believed that the understanding gained from this research will be useful for the design and operation of ramp metering.
Incorporation of Transportation User Perception into Evaluation of Service Quality of Signalized Intersections
Authors: Lee Dongmin , Kim Tae-Gyu , Pietrucha Martin T.
Published: January 2008

Concepts of transportation service quality are related to efforts to evaluate driving conditions and the level of satisfaction that transportation users perceive. However, few data have been gathered from actual users about perceived service quality. A new method is developed for the evaluation of transportation service quality using a fuzzy aggregation and a cultural consensus analysis technique. After a literature review was conducted, six analysis criteria that showed promise as relevant indicators were selected to apply the developed method to assess the service quality of signalized intersections. With the use of a fuzzy weighted-average technique on six criteria, individual perceptions regarding the service quality of signalized intersections were evaluated. Then, the weight of an individual's perceptions, measured with consensus analysis, was applied to estimate a more realistic, aggregated overall service quality rating of a signalized intersection. Through the consensus analysis, the competence scores–which indicate how “correct” and relatively important each individual's response is–were estimated and used for each participant. Experimental results indicate that user perceptions of transportation service quality fall in a narrow measurable range of the scale constructed to perform this measurement. In other words, users' perceptions are not easily distinguished and vary greatly by individual. Therefore, user-perceived service quality ratings do not correspond to the level of service evaluated using the Highway Capacity Manual method. Ratings of user-perceived service quality of signalized intersections evaluated by using the new fuzzy aggregation method are in better agreement with the actual perceptions that people hold than those obtained by using a more conventional method.
Total Approach Capacity at Signalized Intersections with Shared and Short Lanes
Authors: Wu Ning
Published: January 2008

An empirically calibrated theoretical model is presented for the estimation of total approach capacity at signalized intersections with shared and short lanes. The model extends the theoretical capacity formula for shared and short lanes at unsignalized intersections (previously introduced by the author) to signalized intersections. The model accounts for the stochastic nature of traffic flow and the effect of queue blockage on the short turn lanes. The VisSim simulation package was used to generate a comprehensive database for model calibration under different lane and signal-control conditions. The proposed model can be used for arbitrary lane and signal-timing configurations. Explicit equations are given for signalized intersections with simple shared- and short-lane configurations. Detailed monographs are prepared for practical applications.
Assessing the Impact of Turning Vehicles on Pedestrian Level of Service at Signalized Intersections
Authors: Hubbard Sarah M. L. , Awwad Ramzi J. , Bullock Darcy M.
Published: January 2008

The Highway Capacity Manual provides two methods, based on delay and space, for the assessment of pedestrian level of service (LOS) at signalized intersections. Current procedures for evaluating pedestrian LOS are examined, and results indicate that these procedures do not adequately reflect the negative impact of turning vehicles. Pedestrian LOS measures are proposed to reflect not only pedestrian delay and space but also traffic interruptions, freedom of movement, and comfort. These measures are consistent with LOS measures currently used for freeway segments and ramp merge areas. The percentage of compromised pedestrian crossings is proposed as a means to quantify the negative impact of turning vehicles on pedestrian service and as a LOS measure at signalized intersections. A pedestrian crossing is designated as compromised if a pedestrian is delayed or is forced to change travel path or speed in response to a turning vehicle. The percentage of compromised pedestrian crossings was assessed for 13 crosswalks. Results of the assessments illustrate that as right-turn volumes increase, the percentage of compromised pedestrian crossings increases. The proposed method provides an objective engineering tool for measuring the impact of turning vehicles on pedestrian service. It may be appropriate to use this measure to quantify the need for pedestrian improvements (e.g., if the percentage compromised exceeds 15%, then it may be appropriate to implement a leading pedestrian interval or other enhancement).
Field Measurement of Approach Delay at Signalized Intersections Using Point Data
Authors: Kebab Wassim , Dixon Michael P. , Abdel-Rahim Ahmed
Published: January 2008

Delay is considered one of the most important measures of effectiveness used to design, optimize, and evaluate the operation of signalized intersections. Many methods have been proposed to measure delay; however, none of those found in the literature has been tested against delay derived from tracking vehicles to evaluate accuracy. A new point detection-based method to measure approach delay in the field is presented. In contrast to other methods, this method produces more detailed delay measurements because it measures the delay by turning movement and does so with simple point data. Data for this research were collected from video footage for signalized intersections, where vehicle tracking was used as the benchmark and the Highway Capacity Manual queue delay was collected for comparison purposes. Results of the comparison indicate that the proposed method accurately measures delay.
Estimating Truck Equivalencies for Freeway Sections
Authors: Rakha Hesham , Ingle Anthony , Hancock Kathleen , Al-Kaisy Ahmed
Published: January 2008

In the Highway Capacity Manual (HCM), passenger car equivalents (PCEs) are used to convert a mixed-vehicle stream into an equivalent passenger car stream. The 2000 edition of the HCM reports PCEs for basic freeway segments as a function of the proportion of heavy vehicles, grade section steepness, and grade section length. These PCEs are reported for a typical truck with a weight-to-power ratio of 76 to 90 kg/kW (125 to 150 lb/hp). The HCM procedures are extended by using INTEGRATION software to develop PCEs for a broader range of vehicle weight-to-power ratios. In addition, the effects of pavement type and condition, truck aerodynamic treatment, number of freeway lanes, truck speed limit differential, and level of congestion are considered in the development of these PCEs. The calculation of PCEs for multiple-truck weight-to-power ratio populations is also examined and found to be not significantly different from PCE factors for single-truck weight-to-power ratios. The PCE values are tabulated in a format compatible with that used in the HCM 2000 capacity and level-of-service procedures.
Errors in Analyses for Capacity and Timing Design of Signalized Intersections in Absence of Steady Queue Discharge Rates
Authors: Lin Feng-Bor , Chang Chiung-Wen , Tseng Pin-Yi
Published: January 2008

Many models for the analysis of capacity and signal timing of signalized intersections are based on the assumption that queue discharge will quickly reach a steady maximum rate after the green interval begins. This assumption leads to a common practice of using saturation flow and lost time as parameters in modeling the requirements for lane capacity, intersection performance, and signal timing. However, recent field data indicate that the queue discharge rate may continue to increase long after green onset. For this type of queue discharge characteristic, the traditional applications of lost time and saturation flow may result in significant errors when lane capacity and modeling optimal cycle length are estimated. The extent of such errors is assessed on the basis of the queue discharge characteristics observed in 38 urban traffic lanes.
Arrival-Based Uniform Delay Model for Exclusive Protected-Permitted Left-Turn Lane at Signalized Intersections
Authors: Wang Ming-Heng , Benekohal Rahim F.
Published: January 2008

Protected-permitted left-turn (PPLT) control strategies at signalized intersections are used to improve operational efficiency; however, only limited research has been done in modeling the delay for such phasing. The development and validation of uniform delay models for exclusive left-turn lanes with PPLT phases are presented. The proposed models are based on the arrival-based delay method, which directly considers the effects of platoon arrival rate and platoon duration in model development. Two arrival flow rates (one for platoon and one for nonplatoon) and two saturation flow rates (one for protected phase and one for permitted interval) were used to develop the delay models for PPLT. Results of a comparison of the control delays from the proposed models and the Highway Capacity Manual models with simulation results from CorSim indicated that the proposed models estimate the control delay more accurately.
Travel Time Measurement Using Toll Infrastructure
Authors: Soriguera Francesc , Thorson Leif , Robusté Francesc
Published: January 2008

Travel time and its reliability are key factors in traffic management systems. They are the best indicators of the level of service in a road link and perhaps the most important variables for measuring congestion. A new approach is presented: it estimates highway travel time with the use of the existing toll highway infrastructure. A simple, efficient algorithm was developed to estimate the single-section travel time (i.e., time required to travel between two consecutive ramps on the highway) and the exit time for each ramp (i.e., time required to travel along the exit link plus the time required to pay the fee at the toll gate). With a combination of these two estimations, all required route travel times can be calculated. The proposed algorithm overcomes some limitations of other methods, such as information delay in long routes and excess travel time estimation due to accumulated exit times. The method was applied to the AP-7 highway near Barcelona, Spain, and the results obtained were reasonable and accurate.
Factors Affecting Bicycling Demand
Authors: Dill Jennifer , Voros Kim
Published: January 2008

The levels of bicycling in the United States, particularly for nonrecreation purposes and among adults, are low. Only about 1% of the trips that people make in the United States are on bicycles, and less than 5% of trips under 1/2 mi are made on bicycles. Factors influencing the rates of cycling include demographics and environmental factors. Environmental factors can be measured both objectively (e.g., number of miles of bike lanes, average temperature, and street connectivity) and subjectively (e.g., people's ratings or perceptions of the bicycling environment). People's attitudes about travel and mobility likely play a role. This paper uses the results from a random phone survey of adults in the Portland, Oregon, region to explore the relationships between levels of cycling and demographics, objective environmental factors, perceptions of the environment, and attitudes. The survey revealed several significant differences, although additional analysis is necessary. Objective measures of proximity to off-street trails and bike lanes was not associated with higher levels of cycling. However, positive perceptions of the availability of bike lanes was associated with more cycling and the desire to cycle more. Higher levels of street connectivity were associated with more cycling for utilitarian trips.
Network Evaluation Tool to Improve Real and Perceived Bicycle Safety
Authors: Klobucar Michael S. , Fricker Jon D.
Published: January 2008

Bicycles offer a promising transportation alternative to private motor vehicles, especially in areas with congestion, poor air quality, and high fuel prices. The study on which this paper is based sought rational methods for determining the most efficient use of the available funds to improve bicycle transportation. A bicycle network analysis tool was developed to assess the networkwide level of service offered to bicyclists in a study area. The tool uses route length and measures of perceived safety to quantify the bicycle friendliness of a street network. The tool can be used to compare networks and assist with the selection of locations for bicycle facility improvements.
Bicycle Level of Service for Arterials
Authors: Petritsch Theodore A. , Landis Bruce W. , Huang Herman F. , McLeod Peyton S. , Lamb Daniel , Farah Waddah , Guttenplan Martin
Published: January 2008

This paper documents a study sponsored by the Florida Department of Transportation (FDOT) to create a model that predicts how bicyclists perceive the arterial roadway environment. It builds on the highly successful adopted segment and intersection bicycling level of service (LOS) models. Data for the new bicycle LOS for arterials model were obtained from FDOT's innovative Ride for Science field data collection event and video simulations. The data consisted of participants' perceptions of how well roadways met their needs as they rode selected arterial roadways or viewed simulations of those and other roadways. The bicycle LOS for arterials model is based on Pearson correlation analyses, stepwise regression, and PROBIT modeling of approximately 700 combined realtime perceptions (observations) from bicyclists riding a course along arterial roadways. An additional 700 combined perceptions obtained from the participants viewing a video simulation (discussed in another paper) were used to refine the model for arterial roadways. The study participants represented a cross section of individuals by age, gender, riding experience, and residency. The bicycle LOS for arterials model provides a measure of the bicyclist's perspective on how well an arterial roadway's geometric and operational characteristics meets his or her needs. Although further hypothesis testing may be conducted in a future study, this model is highly reliable, has a high correlation coefficient (if2 = .74) with the average observations, and is transferable to the vast majority of metropolitan areas in the United States.
Mobility Patterns of Motorcycle and Moped Riders in Greece
Authors: Yannis George , Golias John , Spyropoulou Ioanna , Papadimitriou Eleonora
Published: January 2008

This paper investigates the mobility patterns of powered two-wheeler riders in comparison with those of passenger car drivers in Greece, a country in which an increased rate of two-wheeler ownership and related traffic is observed. A nationwide travel survey targeted at active two-wheeler and passenger car drivers was carried out for that purpose. The results of the survey were exploited in two ways. First, the use of the vehicle types examined in Greece was investigated in relation to driver characteristics by calculation of the respective sample distributions. The results demonstrated a clear difference between vehicle ownership rates and vehicle use rates by vehicle type. Moreover, the mobility patterns of each vehicle type were compared on the basis of the average yearly mileage traveled in relation to driver (age, gender, experience), vehicle (engine size), type of trip (weekday or weekend), and road environment (area type, lighting conditions, road type). The findings indicated that driver gender, age, and experience appeared to be a stronger determinant of mobility patterns than vehicle type. But different mobility patterns among vehicle types in different road environments were identified; this suggests that mopeds and motorcycles are preferred for particular types of trips (e.g., traveling in residential areas and weekdays during the daytime), whereas passenger cars may be used in all cases.
Dynamic Network Simulation–Assignment Platform for Multiproduct Intermodal Freight Transportation Analysis
Authors: Mahmassani Hani S. , Zhang Kuilin , Dong Jing , Lu Chung-Cheng , Arcot Vishnu Charan , Miller-Hooks Elise
Published: January 2008

This paper develops a dynamic freight network simulation–assignment platform for the analysis of multiproduct intermodal freight transportation systems. At the core of the platform is a model framework for the mode–path assignment problem in multimodal freight transportation networks. The framework consists of three main components: a multimodal freight network simulation component, a multimodal freight assignment component, and a multiple product intermodal shortest path procedure. The freight network simulation component incorporates a bulk queuing model to evaluate transfer delay experienced by shipments at intermodal transfer terminals, classification yards, and ports. The multimodal freight assignment component determines the network flow pattern from a mode–path alternative set calculated by the multiple product intermodal shortest path procedure, based on the link travel costs and node transfer delays from the multimodal freight network simulation component. This model can represent individual shipment mode–path choice behavior, consolidation policy, conveyance link moving, and individual shipment terminal transfer in an iterative solution framework.
Dynamic Decision Making for Less-Than-Truckload Trucking Operations
Authors: Hejazi Behrang , Haghani Ali
Published: January 2008

Of modes of transportation, trucking remains the shipping choice for many businesses, and its market share is increasing. Less-than-truckload (LTL) trucking companies provide consolidated transportation whereby several customers are served simultaneously by the same truck, and shipments need to be consolidated at terminals to build economical loads. Intelligent transportation system technologies offer the possibility of con-trolling the operations in real time. Prior research efforts have considered real-time acceptance or rejection of shipping requests, but mostly have focused on truckload trucking operations. This study attempts to use real-time information in decision making for LTL carriers in the dynamic environment and presents a mathematical formulation for solving the problem. A decision-making procedure and a decision-support application are developed and presented. Numerical experiments are constructed to study the behavior of the system under different demand and supply situations to check the accuracy of the mathematical problem, and to study the characteristics of the LTL trucking operations.
Impact of Designated Secure Rest Facilities on Single-Lane Truck-Dispatching Productivity
Authors: Morris Steven M. , Erera Alan L. , White Chelsea C.
Published: January 2008

This paper develops an approach for analyzing how restricting rest (sleep) locations for long-haul truckers may affect operational productivity, given hours-of-service regulations. Productivity is measured by the minimum number of unique drivers required to execute a set of load requests feasibly over a known planning horizon. When drivers may stop for rest at any location, they should be able to maximize utilization under regulated driving hours. When drivers may stop for rest only at certain discrete locations, drivers may suffer decreased utilization. The framework and results developed in this paper should be especially useful in the analysis of truck transportation of security-sensitive commodities, such as food products and hazardous materials, for which there exists strong external pressure to ensure that drivers rest only in secure locations to reduce risks of tampering. The analysis considers the simplest case, in which all loads to be transported move along a single lane. The paper presents an optimal tree search algorithm for determining the minimum number of drivers required to cover a set of loads given a set of allowed rest locations. Because the optimal approach is often computationally burdensome, the paper also presents and analyzes a set of simple heuristics for determining feasible load-to-driver assignments that can augment the search for the true minimum. Analysis of a sample data set demonstrates the approach and indicates that for lanes of realistic length, the productivity impact of restricting rest to a small number of discrete locations is likely to be small.
Multiobjective Model and Solution Method for Integrated Forward and Reverse Logistics Network Design for Third-Party Logistics Providers
Authors: Lee Der-Horng , Bian Wen , Dong Meng
Published: January 2008

Reverse logistics—that is, the distribution activities involved in product returns—is receiving growing attention. Because of the difference and interaction between the forward and reverse distributions, how to integrate the forward and reverse channels has become an emerging issue. Few studies have attempted to integrate the forward and reverse distributions. Furthermore, the increasing opportunities for cost savings and customer satisfaction in such integrated distribution have prompted third-party logistics providers (3PLs) to get involved in forward and reverse logistics operations. This paper first develops a multiobjective model considering activities of the 3PLs for forward and reverse distributions simultaneously. Two objectives are included in the proposed model: (a) maximization of the returned products shipped from customers back to the collection facilities and (b) minimization of the total costs associated with the forward and reverse logistics operations. A fuzzy goal programming approach is applied to determine the compromise solution for the multiobjective model. A genetic algorithm with two subalgorithms is then developed to solve the problem. Numerical experiments are presented to demonstrate the applicability of the formulated model and the proposed solution method.
A Priori Performance Measures for Arc-Based Formulations of Vehicle Routing Problem
Authors: Ordóñez Fernando , Sungur Ilgaz , Dessouky Maged
Published: January 2008

The vehicle routing problem (VRP) is a central problem for many transportation applications. Although it is well known that it is difficult to solve, how much of this difficulty is caused by the formulation of the problem is less understood. This paper experimentally investigates how the solution times to solve a VRP with a general integer programming (IP) solver are affected by the formulation of the VRP used. The different formulations are evaluated by examining solution efficiency as a function of several a priori performance measures based on the data parameters. The experimental results show how the solution run times are sensitive to problem parameters; in particular, the sensitivity of formulations to the coefficient of variation of the cost matrix of travel times is explained by two interacting factors.
Video Transit Training for Older Travelers
Authors: Shaheen Susan A. , Rodier Caroline J.
Published: January 2008

This study applied principles of social learning and marketing to develop a transit training video for residents of the Rossmoor Senior Adult Community in California. The video features familiar community members successfully navigating specific concerns and problems related to transit use in accessing key community destinations (shopping, health care, and the nearest San Francisco Bay Area Rapid Transit District station). Residents were recruited to complete questionnaires before and after viewing the video to evaluate its effectiveness. Video messages that were aimed at educating viewers on how to obtain transit, cost, and payment information generated a significant and positive attitudinal change. However, respondents reported that the video did not adequately address the difficulties associated with reading schedules and climbing stairs at transit stations. Survey results also indicate a significant and positive change in respondents' future use of a broader range of Internet-related information sources. The results also reveal a significant and positive change among respondents in using transit services to the specific destinations presented in the video. However, results are mixed on whether participants might take transit to general destinations not explicitly represented in the video.
Individual and Neighborhood Determinants of Perceptions of Bus and Train Safety in Chicago, Illinois
Authors: Yavuz Nilay , Welch Eric W. , Sriraj P. S.
Published: January 2008

Individuals decide to use public transit in part on the basis of their perception of transit safety, which is determined by various individual and environmental factors. This paper adopts a multilevel approach to analyze how perceptions of bus and train safety in Chicago, Illinois, vary as a function of person-level characteristics—gender, age, ethnicity, income, and frequency of transit ridership—and neighborhood-level characteristics—perceived neighborhood disorder, population density, and level of poverty. Hierarchical linear modeling is applied to a unique data set that combines data from three different sources: Chicago Transit Authority data on individual-level perceptions of transit safety and individual demographics, Chicago Alternative Policing Strategy data on perceptions of neighborhood disorder at the zip code level, and U.S. Census zip code–level demographic data. Findings show that the individual-and zip code–level effects differ depending on whether the estimation predicts bus or train safety perceptions. Additionally, while higher-income individuals and African Americans report lower levels of perceived bus safety, there is an additional zip code effect: low-density and high-poverty areas and neighborhoods with high levels of disorder have significantly lower levels of perceived bus safety. Management and policy implications of the study for both the transit agency and the community in which service is being offered are discussed.
Predicting Bus Arrival Time on the Basis of Global Positioning System Data
Authors: Sun Dihua , Luo Hong , Fu Liping , Liu Weining , Liao Xiaoyong , Zhao Min
Published: January 2008

The ability to obtain accurate predictions of bus arrival time on a real-time basis is a vital element to both bus operations control and passenger information systems. Several studies had been devoted to this arrival time prediction problem; however, few resulted in completely satisfactory algorithms. This paper presents a new system that can be used to predict the expected bus arrival times at individual bus stops along a service route. The proposed prediction algorithm combines real-time location data from Global Positioning System receivers with average travel speeds of individual route segments, taking into account historical travel speed as well as temporal and spatial variations of traffic conditions. A geographic information system–based map-matching algorithm is used to project each received location onto the underlying transit network. The system is implemented as a finite state machine to ensure its regularity, stability, and robustness under a wide range of operating conditions. A case study on a real bus route is conducted to evaluate the performance of the proposed system in terms of prediction accuracy. The results indicate that the proposed system is capable of achieving satisfactory accuracy in predicting bus arrival times and perfect performance in predicting travel direction.
Simulation Study of Bus Signal Priority Strategy
Authors: Liao Chen-Fu , Davis Gary A.
Published: January 2008

Providing signal priority for buses has been proposed as an inexpensive way to improve transit efficiency and productivity and to reduce operation costs. Bus signal priority has been implemented in several U.S. cities to improve schedule adherence, reduce transit operation costs, and improve customer ride quality. Current signal priority strategies primarily utilize sensors to detect buses at a fixed or preset distance away from an intersection. Traditional presence detection systems, ideally designed for emergency vehicles, usually send a signal priority request after a preprogrammed time offset as soon as transit vehicles are detected without the consideration of bus readiness. The objective of this study is to take advantage of the already equipped Global Positioning System and automated vehicle location system on the buses in Minneapolis, Minnesota, and to develop an adaptive signal priority strategy that could consider bus schedule adherence, number of passengers, location, and speed. Buses can communicate with intersection signal controllers by using wireless technology to request signal priority. Communication with the roadside unit (e.g., traffic controller) for signal priority may be established by using the readily available wireless local area network (WLAN) 802.11x or the dedicated short-range communication (DSRC) 802.11p protocol currently under development for wireless access to and from the vehicular environment. This paper describes the proposed priority logic and its evaluation with the use of microscopic traffic simulation. Simulation results indicate that a 12% to 15% reduction in bus travel time during a.m. peak hours (7 to 9 a.m.) and a 4% to 11% reduction in p.m. peak hours (4 to 6 p.m.) could be achieved by providing signal priority for buses. Average bus delay time was reduced in the range of 16% to 20% and 5% to 14% during a.m. and p.m. peak periods, respectively.
Evaluation of Transit Signal Priority and Optimal Signal Timing Plans in Transit and Traffic Operations
Authors: Muthuswamy Satyanarayana , McShane William R. , Daniel Janice R.
Published: January 2008

Transit signal priority (TSP) systems have been in place for several years. Traffic simulation models are frequently applied to evaluate the benefits of such treatments before implementation. These benefits can take several forms, including reduced travel time for transit customers, improved schedule adherence, and reduced operating costs for the transit provider. This paper reports a case study that highlighted and embodied the following issues: (a) if signal timing is optimized, the TSP may provide only incremental benefits and not be a cost-effective investment; (b) if signal plans are not updated as often as needed, TSP may provide a way of adapting the base signalization, providing much of the benefit of signal plan updates; (c) side-street traffic does not always suffer because of TSP, nor does main-street nonbus traffic; (d) some critical intersections, with heavy competing volumes, may need to be dropped from the TSP plan to have no excessive adverse impact on the cross street, which may itself be an arterial; and (e) bus travel time reductions can result in fewer buses needed to serve the demand at the same level of service and thus reduce bus transit operating costs. Simulation was an important and cost-effective tool in this case study.
Effectiveness of Bus Priority Lane as Countermeasure for Congestion
Authors: Sakamoto Kunihiro , Abhayantha Chandana , Kubota Hisashi
Published: January 2008

The main objective of this research is to identify the effectiveness of the bus priority lane in Shizuoka City, Japan, as a countermeasure for traffic congestion. Shizuoka City, the capital of Shizuoka Prefecture in Japan, suffers from frequent traffic congestion. To tackle this problem, authorities of Shizuoka City tested a pilot project that implemented bus rapid transit (BRT) strategies. This project included a bus priority lane along a 3-km segment and a bus priority signal system. The project data were obtained mainly through traffic surveys, bus surveys, and questionnaire surveys, which were conducted by the authors and by Shizuoka City authorities. All these surveys were carried out twice, before and after the implementation of BRT strategies. After priority treatments were introduced, the number of vehicles using the main road was reduced. Also, queue-length and jam-length measurements showed signs of easing of traffic congestion, and travel times of general vehicles were improved. Although the change associated with total travel time of buses was not statistically significant, it still showed a reducing trend. However, travel times of buses, excluding dwelling times, showed a significant reduction. The difference of significance associated with the above travel parameters was mainly caused by the increase incurred in dwelling times of buses. It was evident that the smoothness of traffic flow along the bus lane as well as along the general traffic lane was improved by the BRT project.
Measuring Demand Management Impacts in a Sustainable Compliance Environment for the Americans with Disabilities Act
Authors: Menninger-Mayeda Heather , Rogers Erin , Wiemiller Dana , Sampson Patrick , Davis Gracie
Published: January 2008

This paper considers the hypothesis that growth management of specialized transportation demand can effectively influence growth in paratransit services complementary to the Americans with Disabilities Act (ADA), contributing to financially sustainable ADA compliance. Federal policies to implement the Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users and documented field experiences of ADA complementary paratransit services speak to the challenges of balancing compliance with consumers' needs. The Orange County Transportation Authority (OCTA), Orange County, California, is creating sustainable strategies that comply with the law and provide mechanisms deep within the community to create alternative services to meet specialized transportation needs. This paper reports on implementation of an ADA demand management plan, tracking the impact of its strategies. Focus areas include (a) paratransit service policies, (b) fixed-route service policies, and (c) coordination with community-based providers. Interventions affect the three levers on costs of total trips, efficiency of those trips, and unit costs of service. Eleven specific strategies and measures of these are presented. Longitudinal data are examined to identify impacts on OCTA's Access paratransit program in relation to trip bookings, productivity, and unit and total costs. Actual ridership and revenue-hour data are contrasted with projections of OCTA's ADA demand estimation tool, its 99% confidence level anticipating significant, continuing trip growth. The paper concludes that it is possible to achieve a growth in the program that is less than the growth in available funds—in measurable ways—through multiple strategies. These include partial funding by the transit authority of community-based transportation alternatives.
Exploring Negative Experiences and User Loyalty in Paratransit
Authors: Joewono Tri Basuki , Kubota Hisashi
Published: January 2008

Negative experiences, commonly expressed in the form of complaints, are not usually considered in the operation of paratransit, especially in developing cities. There have been few studies of negative experiences with paratransit service; that makes it difficult for the authority in charge to plan the improvement agenda. Paratransit (jitney) in this study refers to a public mode of transport of passengers, owned and operated by private individuals or small enterprises. This study aims to explore the users' negative experiences and their relation with the users' perceptions of overall satisfaction and loyalty. The study employs a questionnaire survey distributed to paratransit users in the city of Bandung, Indonesia. The analysis is conducted by using structural equation modeling. The findings illustrate the actual order of the negative experiences and indicate that the issue of quality of life has not been viewed as a primary consideration. Paratransit users are still highly concerned about the fulfillment of their mobility needs. This fact underlines the different perceived levels of importance between developed and developing countries. In addition, this study endeavors to explore the relationship between negative experience, loyalty, and overall satisfaction. Because the relationship is supported by the result of analysis, the proposed model confirms the logical relationship and implies the correlation of theoretical analysis with reality. Thus, this study can be incorporated into the design of an improvement agenda.
Growth and development of female dancers aged 8–16 years
Authors: Steinberg Nili , Siev‐Ner Itzhak , Peleg Smadar , Dar Gali , Masharawi Youssef , Hershkovitz Israel
Published: January 2008

Little data are available on the growth and development of young female dancers. The objective of this study was to determine whether the body structure and adipose tissue distribution of dancers aged 8–16 years differ from that of non‐dancer girls. Our cross‐sectional study included a group of 1,482 female dancers, aged 8–16 years, and a control group of 226 female non‐dancers of similar age cohorts. Fourteen anthropometric measurements were recorded and 15 indices calculated. In none of the linear anthropometric measures, were significant differences found between the two groups. The only significant difference relates to the extent and distribution of adipose tissue: At age 8, both groups show similar weight while at age 13 non‐dancers are significantly heavier than dancers (48.4 ± 9.8 kg for non‐dancers and 40.6 ± 8.7 kg for dancers). At age 15, weight differences between the two groups decrease to only 2 kg. The differences in weight are also expressed in skinfold thickness and chest circumference. Patterns of adipose tissue distribution differ between the two groups. Mean age at menarche was 13.1 years among dancers and 12.3 years in non‐dancers. In conclusion, musculoskeletal development was found to be very similar in dancers and non‐dancers. The specific body type reported for professional dancers is more likely acquired via “teacher's selection” and not training programs. Parents should not dread the possibility that dance training will delay the growth or reduce the height of their daughters. Am. J. Hum. Biol., 2008. © 2008 Wiley‐Liss, Inc.
The second to fourth digit ratio (2D:4D) in women with and without human papillomavirus and cervical dysplasia
Authors: Brabin Loretta , Roberts Stephen A. , Farzaneh Farah , Fairbrother Eleanor , Kitchener Henry C.
Published: January 2008

Persistent infection with human papillomavirus (HPV) is associated with a high risk of cervical intraepithelial neoplasia (CIN) and disease progression is influenced by host hormonal factors. The role of fetal exposure to sex steroids has not been explored. The study compared the second to fourth digit ratio (2D:4D), a marker of exposure to fetal androgens, among women with and without HPV and CIN. Data were available from two studies in which HPV, 2D:4D and descriptive variables were assessed cross‐sectionally at sexual health clinics. One study (case‐control) also assessed cervical smears or biopsies, and some women were retested for persistent HPV. Using these data, 2D:4D was compared among groups defined by cervical smear and HPV result. The cross‐sectional data included 90 adolescents and 240 nonadolescents. White women had a significantly higher 2D:4D than other ethnic groups. In the case‐control analysis (n = 263), after controlling for ethnicity, women who developed CIN were significantly more likely to have a higher 2D:4D compared with HPV‐negative women. A similar, nonsignificant trend was observed among women with a persistent HPV infection. Conclusion: Lower fetal androgen exposure may predispose to persistent HPV and increased risk of CIN. Am. J. Hum. Biol., 2008. © 2008 Wiley‐Liss, Inc.
Metaphyseal chondrodysplasia, upper limb mesomelia and normal height (mesomelic dysplasia camera type): Second report in a Mexican patient
Authors: Becerra‐Solano L.E. , Castañeda‐Cisneros G. , Bañuelos‐Acosta R. , Sánchez‐Corona J. , García‐Ortiz J.E.
Published: January 2008

Mesomelic dysplasias (MD) are a group of skeletal disorders with exclusive or predominant shortness of the middle segment of the limbs, with or without involvement of the hands/feet or other body parts. Short stature is a usual consequence due to involvement of the lower limbs. In 2003, Camera and Camera reported an unusual upper limb MD with normal stature and radiological evidence of long bone metaphyseal dysplasia. Here, we describe a Mexican patient showing a similar clinical and radiological phenotype, in addition to esophageal atresia, palpebral ptosis and slight lower limb asymmetry. This represents the second case reported in the literature, corroborating the existence of this rare entity. © 2008 Wiley‐Liss, Inc.
Yunis–Varon syndrome: Further delineation of the phenotype
Authors: Basel‐Vanagaite Lina , Kornreich Liora , Schiller Ofer , Yacobovich Joanne , Merlob Paul
Published: January 2008

Yunis–Varon syndrome (YVS) is a rare autosomal recessive condition characterized by limb defects, ossification defects, generalized hypotrichosis and, frequently, a severe neonatal course. The molecular basis is unknown. We report on a newborn infant with previously undescribed findings, including hydrops fetalis, primary pulmonary hypertension and unusually severe abnormalities of toes. We review clinical data on 22 published cases in order to delineate the phenotype of this condition. Clinical recommendations for prenatal and postnatal evaluation of patients and fetuses at risk are discussed. © 2008 Wiley‐Liss, Inc.
Denys–Drash syndrome and congenital diaphragmatic hernia: Another case with the 1097G > A(Arg366His) mutation
Authors: Antonius Timothy , van Bon Bregje , Eggink Alex , van der Burgt Ineke , Noordam Kees , van Heijst Arno
Published: January 2008

Congenital diaphragmatic hernia (CDH) is a disorder of the development of the lung and diaphragm and is associated with pulmonary hypoplasia and pulmonary hypertension. Denys–Drash syndrome (DDS) is a well‐known syndrome caused by several different germline mutations in the WT1‐gene. CDH in DDS is rare. We present the third case of CDH with clinical features of DDS and the same, rare Arg366His mutation in the WT1‐gene, as reported in the other two known cases. This report provides additional evidence that WT1 mutations can result in diaphragmatic hernia. © 2008 Wiley‐Liss, Inc.
Compatibility effect of radiation‐grafting‐functionalized styrene–butadiene–styrene on polyamide 6/styrene–butadiene–styrene blends
Authors: Zhang Yan , Li Yintao , Zhao Sufang , Xie Leidong , Sheng Kanglong
Published: January 2008

Styrene–butadiene–styrene (SBS) was grafted with dibutyl maleate (DBM), methacrylic acid (MAA), or maleic anhydride (MAH) by 60Co γ‐rays. The grafted SBS was blended with polyamide 6 (PA6). The compatibility of the PA6/SBS blends was studied with scanning electron microscopy and rheological measurements. The results showed significant improvement in the compatibility of PA6 blended with MAH‐ or MAA‐grafted SBS, with the former being more effective, whereas grafting DBM was ineffective in this respect. Mechanisms of the compatibility enhancement and ineffectiveness are discussed. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Electron spin resonance and optical studies of poly(methylmethacrylate) doped with CuCl2
Authors: Abdelaziz M.
Published: January 2008

Poly(methyl methacrylate) doped with CuCl2 was prepared and its electron spin resonance (ESR) spectra and optical properties were studied. The ESR spectra can be accounted for by the presence of two radicals: Ra and Rb. FTIR spectroscopy reveals that there is no main difference of the spectra due to the addition of CuCl2. The structural modifications are identified by investigating the doping level dependence of the peak heights of certain IR absorption peaks. The optical absorption, transmittance, and reflectance measurements were performed for prepared samples. The doping level (W) dependence on the g‐factor (g), asymmetry factor (A), peak‐to‐peak separation (ΔHpp), spin concentration (N), optical energy gap (Eopt), Urbach energy (Eu), refractive index (n), average oscillator wavelength (λo), and average oscillator strength (So) were estimated. It was found that these parameters are changed with doping level. These changes suggest high sensitivity of these films to doping that would suggest the applicability in magnetic and/or optical devices. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Photo and thermal polymerization of epoxides and vinyl ethers by novel sulfonium salts
Authors: Kim Jun Young , Patil Prashant S. , Seo Byoung Jun , Kim Tae Soo , Kim Jinhwan , Kim Tae Ho
Published: January 2008

Novel Sulfonium salts with non‐nucleophilic anions were synthesized and applicability of these salts as initiators was demonstrated by carried out polymerization (photo and thermal) of epoxides as well as vinyl ether monomers. Newly synthesized initiators showed good activity for the photo and thermal polymerization. Synthesis, characterization, and activity of initiators have been described. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008.
Radiation‐induced graft copolymerization of MMA monomer onto UHMWPE: Adhesion improvement
Authors: Kalteh Haji Gorgan , Rezaei Mostafa , Abbasi Farhang , Sheikh Nasrin
Published: January 2008

Graft copolymerization of methyl methacrylate monomer onto ultra high molecular weight polyethylene (UHMWPE) and acid‐etched UHMWPE was conducted using preirradiation method in air in the presence of a Mohr salt and sulfuric acid to improve adhesion to the bone cement. The grafted samples were characterized by Fourier transform infrared (FTIR) spectroscopy, gravimetric method, goniometry, and interfacial bonding strength measurements. The FTIR results showed the presence of ether, carbonyl, and hydroxyl groups for grafted films. The gravimetric results showed that the chromic acid etching and graft copolymerization had a synergetic effect so, the irradiated, then chromic acid etched at room temperature and grafted sample (Rad etch25) had the highest grafting degree. The interfacial bonding strength between UHMWPE and poly methyl methacrylate bone cement was considerably improved by graft copolymerization and chromic acid etching. The surface morphology was studied by scanning electron microscopy. The substitution of polar groups into the backbone of UHMWPE by chromic acid etching and graft copolymerization changed its contact angles with water and methylene iodide and increased its surface energy, as evidenced by contact angle measurements. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008