bluuebunny/crossref_metadata_2025 huggingface dataset:
Efficacy of an Anesthetic Gel in the Reduction of Pain During Impression Making
Authors: Bressan E , Paniz G , Gobbato L , Franco A , Lops D
Published: February 2014

Introduction

Gingival tissue displacement can be an uncomfortable procedure, often performed without injectable local anesthesia. The present study evaluated the efficacy of an anesthetic gel in reducing pain during this procedure.

Material and Methods

Thirty patients undergoing definitive dental impression, for fabricating full-coverage restorations, were evaluated for pain perception on displacement of the surrounding gingival tissues. All the participants were randomly divided into two groups. Five minutes before the insertion of the displacement cord, the anesthetic gel, a mixture of 5% lidocaine and 5% prilocaine, was applied in the sulcus of test group patients. Each patient was asked to complete the Visual Analogue Scale (VAS) and the Verbal Rating Scale (VRS).

Results

In the two scales considered, test group patients showed a statistically significant pain reduction (VAS p=0.0002, VRS p=0.01054) compared to control group patients.

Conclusions

Within the limitations of this study, a clinically significant efficacy of the anesthetic gel was noticed during gingival displacement procedures.
Pure chitosan microfibres for biomedical applications
Authors: Toskas Georgios , Brünler Ronny , Hund Heike , Hund Rolf-Dieter , Hild Martin , Aibibu Dilibaier , Cherif Chokri
Published: February 2014

Due to its excellent biocompatibility, Chitosan is a very promising material for degradable products in biomedical
applications. The development of pure chitosan microfibre yarn with defined size and directional alignment has
always remained a critical research objective. Only fibres of consistent quality can be manufactured into textile
structures, such as nonwovens and knitted or woven fabrics. In an adapted, industrial scale wet spinning process,
chitosan fibres can now be manufactured at the Institute of Textile Machinery and High Performance Material
Technology at TU Dresden (ITM). The dissolving system, coagulation bath, washing bath and heating/drying were
optimised in order to obtain pure chitosan fibres that possess an adequate tenacity. A high polymer concentration
of 8.0–8.5% wt. is realised by regulating the dope-container temperature. The mechanical tests show that the
fibres present very high average tensile force up to 34.3 N, tenacity up to 24.9 cN/tex and Young’s modulus up
to 20.6 GPa, values much stronger than that of the most reported chitosan fibres. The fibres were processed into
3D nonwoven structures and stable knitted and woven textile fabrics. The mechanical properties of the fibres and
fabrics enable its usage as textile scaffolds in regenerative medicine. Due to the osteoconductive properties of
chitosan, promising fields of application include cartilage and bone tissue engineering.
A cocoon immunisation strategy against pertussis for infants: does it make sense for Ontario?
Authors: Lim G H , Deeks S L , Crowcroft N S
Published: February 2014

Binary file ES_Abstracts_Final_ECDC.txt matches
Inter-Professional Practice: From Veterinarian to the Veterinary Team
Authors: Kinnison Tierney , May Stephen A. , Guile David
Published: February 2014

Animal health care is being delivered by an increasing number of professions and occupations. This article takes an inward look at the veterinary team, focusing on the day-to-day life of veterinarians and those with whom they work, such as veterinary technicians/nurses, physical therapists, and farriers. The evolution of the work of the veterinarian should be explored alongside the evolution of closely related occupations, as the current working practice of veterinarians is affected by the practice of these other occupations. An example is given of UK veterinary nurses (similar to veterinary technicians in North America) who are currently undergoing professionalization. Seminal implementations have included a register (2007), disciplinary procedures (2011), a declaration of professional responsibilities (2012), and required continuing professional development for registered veterinary nurses (RVNs). These implementations result in veterinary nurses who are now accountable for their actions. There are many potential benefits to good inter-professional practice for the practice itself, individual team members, clients, and patients, including better results produced by the whole team rather than the sum of the parts, financial benefits to using individuals in lower-paid occupations for shared roles, and greater client satisfaction regarding increased options for treatment. There are, however, many challenges to inter-professional working that center on the interlinked themes of hierarchy (power, status, and the understanding/appreciation of professional roles) and communication (lack of/poor). Inter-professional education (IPE) is suggested as a potential means to overcome these challenges; however, research into IPE exclusively related to the veterinary team is lacking.
Resilient and Permanent Deformation Characteristics of Unbound Pavement Layers Modified by Geogrids
Authors: Tang Xiaochao , Stoffels Shelley M. , Palomino Angelica M.
Published: February 2014

The benefits of geogrids in reducing permanent deformation of flexible pavements are generally recognized and have been shown in numerous studies. In contrast, although resilient moduli of unbound materials are important property inputs in mechanistic–empirical pavement design, the impact of geogrids on the resilient behavior of unbound layers remains unclear from previous studies. This paper focuses on resilient behavior of unbound layers and permanent deformation of subgrades modified by geogrids at the base–subgrade interface. Two sets of tests were conducted on scaled pavements built over two types of soil. Each set of tests consisted of four sections. Three were modified with different geogrids and one was left unmodified as a control. Instruments were installed to measure the subgrades’ resilient and permanent deformations. The pavement layers were tested with a lightweight deflectometer (LWD). Surface deflections and subgrade resilient deformation under impulsive LWD loads were recorded. The test sections were then subjected to repetitive reduced-scale moving-wheel loading. Subgrade resilient and permanent deformations were measured at select intervals of the wheel passes. The measurements of surface deflection and subgrade resilient deformation under the LWD load indicate that the geogrids did not have an appreciable impact on the resilient behavior of the base layer and subgrade. Subgrade resilient deformations, along with the repetitive wheel loads, also suggest that the effects of the geogrids on the resilient responses of the subgrade were not evident. However, two of the geogrids consistently exhibited benefits in reducing permanent deformation in the subgrade.
Evaluation of Seasonal Variation in Mechanistic Responses of Flexible Pavements through use of Falling Weight Deflectometer Data
Authors: Norouzi Meisam , Nassiri Somayeh , Bayat Alireza
Published: February 2014

Flexible pavements in cold regions with frequent freeze and thaw cycles are prone to damage at the start of thawing and during the thaw–recovery season every year. In an attempt to limit damage to the pavement, many highway agencies enforce a spring road ban (SRB) on secondary roads during the thawing period. The Alberta Ministry of Transportation in Canada performs an extensive falling weight deflectometer (FWD) test program during the spring to enhance SRB decision making. This study uses FWD test data from 2000 to 2006 for multiple highway sections in Alberta to investigate the seasonal variation in pavement stiffness and its effect on pavement mechanistic responses. FWD data were used to backcalculate the moduli for the pavement layers, which were then used in multilayer elastic models to predict the pavement critical responses in thawing versus recovery periods. Asphalt Institute models were used to relate the pavement critical responses to fatigue cracking life (Nf) and rutting life (Nd) in thawing versus recovery periods. Nf and Nd dropped by as much as 80% for fatigue cracking and 95% for rutting in the thawing period compared with the recovery period. Further analysis showed that a 50% reduction in the load applied during thawing can result in an approximately 90% increase in both Nd and Nf. The Mechanistic– Empirical Pavement Design Guide software was used to simulate SRB by reducing the maximum applied load by 50% in the thawing period. The results showed a 50% increase in pavement life in rutting and in top-down and bottom-up fatigue cracking.
Viscoelastic Genetic Algorithm for Inverse Analysis of Asphalt Layer Properties from Falling Weight Deflections
Authors: Varma Sudhir , Kutay M. Emin , Levenberg Eyal
Published: February 2014

The falling weight deflectometer (FWD) is a nondestructive test whose results are typically used for backcalculating in situ layer properties of pavements. Most backcalculation methods assume the pavement to be a layered elastic half-space. However, asphalt pavements behave more like multilayered viscoelastic systems, especially in response to small or short-duration load applications. Hence, although elastic analysis is computationally efficient and well accepted in the engineering community, the theory cannot produce the viscoelastic properties of the asphalt concrete (AC) layer. In this study, a new inverse analysis method is proposed to backcalculate both linear elastic and viscoelastic properties of pavement layers as well as the AC time–temperature shift factor. In this method, the FWD load–response history of a single FWD drop and variation in temperature along the depth of the AC layer during the drop are used for performing the computations. The underlying (viscoelastic) forward solver is approximate and disregards dynamic effects; these factors, in return, make it computationally efficient. A genetic algorithm–based optimization scheme is offered to search for the pavement properties. As an example, two sections from the long-term pavement performance study were selected for investigation. The back-calculation results were positive, which indicates that unless a stiff layer exists close to the surface, it should be possible to infer linear viscoelastic properties from a single FWD drop.
Comparative Evaluation of Locked-Wheel and Fixed-Slip Skid Systems
Authors: Fernando Emmanuel G. , Zimmer Richard A. , Mikhail Magdy
Published: February 2014

Most states are using locked-wheel skid trailers to maintain an inventory of skid numbers (SNs) across their highway networks. The locked-wheel skid trailer does not produce the same SN values as the variable-slip and fixed-slip devices. Thus, a need exists to conduct side-by-side tests to compare the measurements from fixed-slip and locked-wheel skid systems. This paper presents results from tests conducted with fixed-slip and locked-wheel friction measurement systems to investigate relationships between the friction numbers obtained from both systems.
Effects of Public Rest Areas on Fatigue-Related Crashes
Authors: McArthur Adam , Kay Jonathan , Savolainen Peter T. , Gates Timothy J.
Published: February 2014

Fatigue-related crashes account for 2.2% to 2.6% of all fatal crashes in the United States on an annual basis. These types of crashes are prevalent in rural areas, and public roadside rest areas were developed largely to alleviate motorist fatigue and reduce the opportunity for such crashes by providing safe parking areas for tired drivers. However, research about the safety effects of rest areas has been limited. Results are presented of a spatial analysis that investigates how a road segment's proximity to a rest area affects the frequency of fatigue-related crashes. Poisson and negative binomial models are estimated for freeways and two-lane highways to isolate the effects of proximity while controlling for other relevant factors, such as traffic volume. The results of these models indicate that the proximity of a road segment to the nearest rest area significantly influences crash frequencies on both freeways and two-lane highways, where traffic volumes tended to have similar effects, although the effects of proximity were slightly more pronounced on two-lane highways. The study results suggest that roadside rest areas provide a safety benefit, and the crash prediction models developed as a part of this research provide a starting point for quantifying these impacts.
Application of Stochastic Gradient Boosting Technique to Enhance Reliability of Real-Time Risk Assessment
Authors: Ahmed Mohamed M. , Abdel-Aty Mohamed
Published: February 2014

This study proposes a new and promising machine learning technique to enhance the reliability of real-time risk assessment on freeways. Stochastic gradient boosting (SGB) is used to identify hazardous conditions on the basis of traffic data collected from multiple detection systems such as automatic vehicle identification (AVI), remote traffic microwave sensors (RTMS), real-time weather stations, and roadway geometry. SGB's key strengths lie in its capability to fit complex nonlinear relationships; it handles different types of predictors and accommodates missing values with no need for prior transformation of the predictor variables or elimination of outliers, as with real-time applications. Boosting multiple simple trees together overcomes the poor prediction accuracy of singletree models and provides fast and superior predictive performance. Three models are calibrated: a full model that augments all available data and another two models to compare explicitly the prediction performance of traffic data collected from different sources (AVI and RTMS) at the same location. The results from the preliminary analysis as well as the calibrated models indicate that crash prediction by AVI is comparable to that by RTMS data. Moreover, the full model achieves superior classification accuracy by identifying about 89% of crash cases in the validation data set with only a 6.5% false positive rate. Because of its superior classification performance and its minimal required data preparation, SGB is recommended as a promising technique for real-time risk assessment.
Feasibility of Incorporating Reliability Analysis in Traffic Safety Investigation
Authors: Yu Rongjie , Shi Qi , Abdel-Aty Mohamed
Published: February 2014

The feasibility of using reliability analysis methods in traffic safety analyses is investigated. The reliability analysis approach, frequently used to evaluate the probability of failure of a specific structural system, has two main outcomes: the reliability index and the design points. Two approaches to using these two outcomes in traffic safety analyses are presented. Data from a mountainous freeway in Colorado are used. The reliability index is used to evaluate the hazardous freeway segments by incorporating the traffic flow parameters provided by radar detectors. The design points are employed to evaluate real-time crash occurrence risk at the disaggregate level with weather parameters. Finally, results of the reliability analysis approach are compared with the results of traditional methods. The reliability analysis method shows promising application in traffic safety studies. With the use of the reliability indexes, the three most hazardous freeway segments are identified. Moreover, with the design points, the accuracy rate of predicting crash occurrence is improved by 10.53% as compared with the logistic regression method.
Surrogate Safety Measure for Simulation-Based Conflict Study
Authors: Wang Chen , Stamatiadis Nikiforos
Published: February 2014

A surrogate measure called the aggregated crash propensity metric (ACPM) is proposed for simulation-based conflict studies to allow for relative comparisons and safety evaluations among intersection designs. A probabilistic crash propensity model is developed to determine the crash probability of simulated conflicts by introducing the distributions of reaction time and maximum braking rates. This model is able to generate the ACPM for three different crash types: crossing, rear end, and lane change. An experimental validation effort was conducted by simulating 12 intersections through the simulation package VISSIM. The surrogate safety assessment model is used to extract useful conflict data for entry into the model to estimate the ACPM. The Spearman rank tests indicate that the ACPM is able to identify the relative safety among traffic facilities and treatments. Notably, the ACPM outperforms the Highway Safety Manual procedures in rank tests. Preliminary efforts to correlate the ACPM with crashes and to use it as a crash predictor indicate that regression models are well fitted for the ACPM and predicted real crash frequency; this finding suggests that its potential is directly linked to real crashes.
Developing Truck Corridor Crash Severity Index
Authors: Qin Xiao , Sultana Most Afia , Chitturi Madhav V. , Noyce David A.
Published: February 2014

According to NHTSA, more than 400,000 truck accidents occurred in 2009 and approximately 7,800 of those were fatal crashes. Compared with extensive studies conducted on freeway truck safety, the research on arterial streets is considerably disproportionate. Making the connections between truck traffic generators, arterial streets are key links in door-to-door deliveries. There is an urgent need to study truck safety on arterial streets because of the strong growth of truck traffic. Truck-related crashes are expected to be reduced through careful planning of the location, design, and operation of driveways, median openings, street connections, and street sections. Through the collection of extensive data on selected arterial corridors that are heavily used by trucks, contributing factors to truck crash frequency and severity were identified with a negative binomial model and multinomial logit model. Corridor truck miles traveled, annual average daily traffic, signal density, shoulder width, and pavement serviceability index and its standard deviation are significant factors for crash frequency prediction. The multinomial logit model identified 12 causal factors for crash severity, such as posted speed limit, lane width, number of lanes, pavement condition index, and undivided roadway portion. Subsequently, a crash severity index for truck arterial corridors was developed. The findings from the study not only will benefit state and local agencies in planning, design, and management of a safer truck arterial corridor, but will also help carriers to optimize their routes from a safety perspective.
Safety Evaluation of Horizontal Curves on Rural Undivided Roads
Authors: Khan Ghazan , Bill Andrea R. , Chitturi Madhav V. , Noyce David A.
Published: February 2014

The objective of this research was to develop prediction models for total crashes and fatal or injury crashes for rural horizontal curves on undivided roads, with a focus on three distinct aspects. The first was an emphasis on assembling a large, high-quality data set. Crash prediction models were developed by using a data set of 11,427 rural horizontal curves on Wisconsin state trunk network roads with more than 13 parameters and four distinct types of crash data sets. The second focus area was to use regression tree analysis in creating a simple model of horizontal curve safety aimed at practitioners of systemic road safety management and creating subsets of data that warranted further analysis. Regression tree results identified the curve radius of approximately 2,500 ft as a significant point below which there is a marked increase in crashes on horizontal curves. The third focus area was to research the effect on horizontal curve crash prediction models of different selection criteria to assemble the crash data set. Models (total and fatal or injury) based on a crash data set with and without crashes in the proximity of intersections were compared. The results show that when crashes on horizontal curves are selected where crash report forms indicate the presence of a horizontal curve, crashes that occur in the proximity of intersections do not affect model results significantly; therefore, the inclusion of such crashes would increase the size of the data set and benefit model development.
Examining Heterogeneity of Driver Behavior with Temporal and Spatial Factors
Authors: Ellison Adrian B. , Greaves Stephen , Bliemer Michiel
Published: February 2014

Temporal and spatial characteristics of the road environment are known to influence driver behavior and, consequently, the risk of a crash that causes injury or fatality. Nonetheless, much of the understanding of the risks of injury and fatality associated with driving relies heavily on police crash records. These records capture the most serious of crashes but underreport other events. Studies that rely on these data sources typically ignore the temporal and spatial factors. Advances in technology have enabled more detailed study of driving on a day-to-day basis and, therefore, provided the opportunity to examine driver behavior for the same driver across time and space. However, this ability has its own challenges. These challenges include extensive intra- and interdriver heterogeneity, which is not apparent when traditional data collection methods are used. A framework and a methodology for isolating the influence of drivers' inherent characteristics on driver behavior are presented. This study was done by constructing temporal and spatial identifiers that controlled for the influence of the road environment. Results include analyses conducted by using empirical driving information collected from 106 vehicles in Sydney, Australia, to examine the effectiveness of this approach. The results indicated that in 80% of road environments there was less intradriver variability in speeding behavior than interdriver variability when temporal and spatial characteristics were accounted for. Clustering and regression analyses for the most frequently observed road environments are also presented. Driver personality characteristics are significant for evening trips home on residential roads, and acceleration profiles are significant in evening trips on roads with 50- and 60-km/h speed limits.
Motion Prediction Methods for Surrogate Safety Analysis
Authors: Mohamed Mohamed Gomaa , Saunier Nicolas
Published: February 2014

Despite the rise in interest in surrogate safety analysis, little work has been done to understand and test the impact of methods for motion prediction, which are needed to identify whether two road users are on a collision course, and to compute several surrogate safety indicators such as the time to collision. The default, unjustified method used in much of the literature is prediction at constant velocity. In this study, a generic framework is presented to predict road users' future positions depending on their current position and their choice of acceleration and direction. This method results in the possibility of generating many predicted trajectories by sampling distributions of acceleration and direction. Three safety indicators—the time to collision, an extended version of predicted post encroachment time, and a new indicator measuring the probability that the road user's attempted evasive actions will fail to avoid the collision—are computed over all predicted trajectories. These methods and indicators are illustrated in four case studies of lateral road user interactions. The evidence suggests that the prediction method based on the use of a set of initial positions seems to be the most robust. Another contribution of this study is to make all the data and code used available (the code as open source) to enable reproducibility and to start a collaborative effort to compare and improve the methods for surrogate safety analysis.
Identification of Crash-Contributing Factors
Authors: Manepalli U. R. R. , Bham Ghulam H.
Published: February 2014

Sample sets of crash data are used to examine the similarities in crash-contributing factors among various counties in the state of Arkansas that have similar effects on spatial autocorrelation. Moran's I and Getis–Ord Gi* statistics were used to determine the correlation, and multinomial logistic regression was used to identify the crash-contributing factors. Seventy-five counties were divided into five categories on the basis of the Z-values of the Getis–Ord Gi* statistic. Depending on the sample data size, for each category crash data from a county or a group of counties were used, and crash-contributing factors were identified on the basis of the crash severity index. Results indicated that most of the crash-contributing factors identified for each category were also identified by the sample crash data from a county or a group of counties in that category. Pulaski County, with the highest Z-value from the first category, had the largest cluster of crashes and identified the highest percentage (55%) of factors that contributed to crashes in the category by using the sample crash data. From the sample data used, the multinomial logistic regression indicated the following factors to be positively associated with crash severity: nighttime driving, driving under the influence of alcohol, roadway gradient, alignment on a curve, rural areas, and collision types head-on and sideswipe-same-direction. The results of this research can be used for better allocation of funds by departments of transportation by analyzing smaller sets of data to identify crash-contributing factors associated with higher levels of crash severity.
Full Bayes Before-and-After Evaluation of Traffic Safety Improvements in City of Edmonton, Canada
Authors: Li Simon Chun-Yin , Sayed Tarek , El-Basyouny Karim
Published: February 2014

The objective of this study was to evaluate the safety performance of a sample of intersections that had been improved with the implementation of certain safety countermeasures targeting right-turn collisions in the city of Edmonton, Canada. A full Bayes approach was used to determine the effectiveness of the improvements by employing a before-and-after design with matched (yoked) comparison groups. Three linear intervention models were considered: a multivariate model that modeled treatment effects as a gradual change, a similar model with the addition of a jump treatment effect, and a univariate model that specifically analyzed right-turn collisions. The results indicated that the safety improvement program was effective; up to 40% of right-turn collisions were reduced. Despite the small sample size, these reductions were statistically significant. The results show the usefulness of the full Bayes technique in performing before-and-after evaluations of traffic treatment programs and in eliminating the need for a reference population and also in allowing for additional types of analysis, including multivariate analysis (modeling collisions of different types and severities at the same time), temporal effects (for both treatment and long-term trends), and greater freedom in the selection of error structure.
Modeling of Passing Events in Mixed Bicycle Traffic with Cellular Automata
Authors: Zhao De , Wang Wei , Li Chenyang , Li Zhibin , Fu Pengming , Hu Xiaojian
Published: February 2014

The primary objective of this study was to use the cellular automata (CA) method to model the characteristics of bicycle passing events in mixed bicycle traffic on separated bicycle paths. The mixed traffic was composed of two types of bicycles: the conventional bicycle (c-bicycle) and the electric bicycle (e-bicycle). The number of passing events and the characteristics of mixed bicycle traffic were investigated in the field on eight physically separated bicycle paths in China. Then a CA model was calibrated with the use of the field data to simulate the passing events in the mixed bicycle traffic. The results showed that the CA model could simulate the features of bicycle passing events well. The simulation results were consistent with field observations. An increase in the ratio of e-bicycles would not significantly increase the number of passing events, but e-bicycles did contribute substantially to passing events in mixed bicycle traffic. E-bicycles were shown to have more stability than c-bicycles, especially in traffic with a high flow rate. The findings of this study could improve the performance of simulation techniques to reflect the actual characteristics of mixed bicycle traffic.
Methodology for Estimating Bicyclist Acceleration and Speed Distributions at Intersections
Authors: Figliozzi Miguel , Wheeler Nikki , Monsere Christopher M.
Published: February 2014

As cities across North America install infrastructure to accommodate a growing number and variety of bicyclists, installation of bicycle-specific traffic signals is a common design element. A recent survey showed a lack of consistency in design and timing. In particular, minimum green signal timing is highly dependent on the assumed acceleration and speed performance of bicyclists, but no detailed methodology exists to estimate these performance values. Recently, AASHTO, the California Department of Transportation, and the National Association of City Transportation Officials issued documents that required the provision of an adequate clearance interval and recommended that, in the determination of this minimum interval field, an investigation of bicyclist speed be conducted. Even if detailed video trajectories are available, the determination of a value for field speed and acceleration is not trivial, because values of speeds and accelerations are a function of time and individual bicyclist performance. The purpose of the research reported here was to develop and apply a general methodology to estimate bicyclist acceleration and speed for traffic signal timing applications. With the use of physical equations of motion, this research analytically derived expressions that could be used to classify an individual bicyclist's performance as a function of the observed acceleration profile. The analysis indicated that four basic acceleration profiles were possible and that the profiles could be obtained with a parsimonious field data collection method. The methodology was applied successfully to two intersections in Portland, Oregon. A detailed statistical analysis showed that the results were intuitive and that the methodology successfully categorized bicyclist performance variations as a result of topography or demographic characteristics.
Public Bikesharing in North America
Authors: Shaheen Susan A. , Cohen Adam P. , Martin Elliot W.
Published: February 2014

Public bikesharing, the shared use of a bicycle fleet by the public, is an innovative mobility strategy that has emerged recently in major North American cities. Typically, bikesharing systems position bicycles throughout an urban environment, within a network of docking stations, for immediate access. Bikesharing services with a basis in information technology (IT) began to emerge in North America approximately 5 years ago. Twenty-eight IT-based programs were deployed between 2007 and March 2013. Twenty-four are operational, two are temporarily suspended, and two are now defunct. This study examined the growth potential of bikesharing in North America on the basis of a survey of all 15 IT-based public bikesharing systems in operation in the United States and all four programs deployed in Canada as of January 2012. These programs accounted for 172,070 users and 5,238 bicycles in the United States and for 44,352 users and 6,235 bicycles in Canada. Early operator understanding of North American public bikesharing is reviewed and emerging trends for prospective program start-ups are discussed.
Characteristics of Multimodal Conflicts in Urban On-Street Bicycle Lanes
Authors: Conway Alison , Cheng Jialei , Peters Diniece , Lownes Nicholas
Published: February 2014

In urban areas, bicycles that travel in bicycle lanes encounter a variety of obstructions, including pedestrians and various types of motor vehicles. Earlier studies focused on the frequency of such events. The goal of this study was to characterize the obstructions. Data were collected in the Manhattan and Brooklyn boroughs of New York City to evaluate specific characteristics (e.g., bicycle lane designs, curb regulations, land use) that might influence the frequency of specific conflict types. A method is described for evaluating the frequency of conflicts between bicycles that travel in on-street bicycle lanes and various other transportation modes and for identifying factors that might affect the frequency of such conflicts.
Built Environment and Household Electric Bike Ownership
Authors: Zhang Yi , Li Yuan , Yang Xiaoguang , Liu Qixing , Li Chaoyang
Published: February 2014

Planners and policy makers have recognized the effects of the built environment on vehicle ownership and use. Within the voluminous literature, however, few studies have examined how the built environment was associated with household electric bike (e-bike) ownership. This study explored the relationship between the built environment and household e-bike ownership in the Chinese context, on the basis of data collected in the Zhongshan Metropolitan Area. The e-bike choice models suggested that household measures dominated the number of household e-bikes, but the models also detected a relationship between several built environment attributes and household e-bike ownership. All else being equal, denser and higher mixed land use development, more connective transportation links, and accessibility to commerce and jobs were related to lower household e-bike ownership. Households located in urban neighborhoods tended to own fewer e-bikes than those in suburban or rural areas. The availability of competitive transportation modes was strongly related to the likelihood of e-bike ownership. The results suggested that policy makers should consider built environment attributes with respect to policies on e-bike ownership and set different policies in different areas according to the variations in the built environments. The findings also suggested that e-bike ownership policies should be integrated with ownership policies on competitive modes and with policies related to public transportation service improvement.
Are Bikeshare Users Different from Regular Cyclists?
Authors: Buck Darren , Buehler Ralph , Happ Patricia , Rawls Bradley , Chung Payton , Borecki Natalie
Published: February 2014

In recent years, bikeshare systems have spread throughout the United States. Despite the increase in systems and users, little is known about how bikeshare member demographics and travel patterns compare with those of traditional bicyclists. To bridge the gap, this study investigated bikeshare system user travel behavior and developed a profile of user demographics through the comparison of short-term (1 day) users and annual members of Capital Bikeshare (CaBi) in Washington, D.C., with profiles of area bicyclists. Data originated from a Washington, D.C., regional household travel survey of 2007–2008, an intercept survey of short-term CaBi users, and an online survey of annual CaBi members. The analysis compared gender, race and ethnicity, age, and student status, as well as socioeconomic status across the surveys. The comparison included trip purpose, helmet use, and travel modes for trips that were replaced by bikesharing. Profiles of CaBi and area cyclists differed with respect to many demographic and socioeconomic characteristics. Compared with area cyclists, CaBi short-term users and annual members were more likely to be female and younger, to have lower household incomes, and to own fewer cars and fewer bicycles and were more likely to cycle for utilitarian purposes. CaBi trips mainly replaced trips made by public transport and by walking. CaBi short-term users and members shared similar characteristics, but short-term users were more likely to ride for recreational purposes and were less likely to wear a helmet. The study results indicated that bikesharing can encourage new segments of society to cycle and can help increase the bicycling mode share overall.
Four Types of Cyclists?
Authors: Dill Jennifer , McNeil Nathan
Published: February 2014

The labeling and the categorizing of cyclists have been occurring for more than a century for a variety of purposes. This study examined a typology developed by the City of Portland, Oregon, that included four categories of cyclists: “the strong and the fearless,” “the enthused and confident,” “the interested but concerned,” and “no way, no how.” Unlike several other typologies, this widely referenced typology was intended to apply to all adults, regardless of their current cycling behavior. An analysis was conducted with data from a random phone survey (n = 908) of adults in the Portland region. Adults were placed into one of the four categories primarily on the basis of their stated comfort level with cycling on a variety of facility types, their interest in cycling as transportation, and their physical ability to bicycle. Nearly all of the sampled population fit clearly into one of the four categories. A majority (56%) of the region's population fit in the interested but concerned category, which was thought to be the key target market to increase the use of cycling as a form of transportation. The analysis indicated that a reduction in traffic speed and an increase in the separation between bicycles and motor vehicles (e.g., cycle tracks) might increase levels of comfort and cycling rates. Women and older adults were underrepresented among the more confident adults and those who currently cycled for transportation.
Evaluation of Innovative Bicycle Facilities in Washington, D.C.
Authors: Goodno Mike , McNeil Nathan , Parks Jamie , Dock Stephanie
Published: February 2014

Two innovative bicycle facilities were installed in Washington, D.C., during 2010 by the District Department of Transportation: buffered center median bicycle lanes on Pennsylvania Avenue, NW, and a two-way cycle track on 15th Street, NW. Both facilities included dedicated road space with buffers between bicyclists and motor vehicles, signal control, and signs and pavement markings. The facilities were designed to increase safety, comfort, and convenience for cyclists. This paper presents the results of a comprehensive study that evaluated the facilities to understand how well they worked for cyclists, motorists, and pedestrians in terms of safety and level of service (LOS) and how they affected behavior and attitudes. The study found that bicycle LOS improved and that bicycle volume on those corridors nearly quadrupled, well above the rate of citywide bicycle use. Motor vehicle LOS was largely unaffected. Signal progression was mixed for bicyclists: contraflow travel on the one-way portion of 15th Street and travel against the dominant direction on Pennsylvania Avenue showed the worst travel time performances. Although bicycle crashes increased on both facilities, the crash rate remained similar on 15th Street to what it had been previously. Pennsylvania Avenue saw a higher crash rate, mainly as a result of illegal U-turns across the bike lanes. In surveys of all travelers on the corridor (i.e., bicyclists, motorists, pedestrians) and nearby residents, the perception of the lanes in general was positive for all users, and the lanes were seen as a positive addition to the community.
Accommodation of Large Trucks in Roundabouts
Authors: Park Lisa , Pierce David
Published: February 2014

Roundabouts increasingly are used as alternatives for signalized and stop-controlled intersections in the United States, where nearly 200 new roundabouts are constructed every year. Proponents often cite numerous safety improvements, including reduced overall crash rates at converted intersections, as justification to increase roundabout development. However, the growing use of roundabouts may inhibit the safe and efficient movement of large trucks because of roundabout design elements that conflict with truck operations. In collaboration with Kansas State University, researchers from the American Transportation Research Institute conducted an online survey of motor carriers to explore features that may hinder roundabout use by large trucks. The survey collected industry observations regarding the challenges experienced by commercial truck drivers in negotiating roundabouts. Those observations are synthesized, and the anecdotal experiences that may allow researchers and roadway designers to identify and categorize unknown roundabout design issues and possible solutions are documented. It is hoped that the research results can be used as the first conversation in a productive dialogue between transportation planners and the trucking industry on the issue of roundabout design for large truck use.
Safety Benefits of Stability Control Systems for Motorcoach Buses
Authors: Woodrooffe John , Blower Daniel , Green Paul E.
Published: February 2014

The potential safety benefits of electronic stability control (ESC) systems for motorcoach buses operating within the United States are analyzed. “Motorcoaches” are defined as flat-front, high-platform buses equipped for intercity or long-distance travel. In recent years, ESC has increasingly become available as standard or optional equipment on motorcoaches. However, national crash databases do not include information that can be used to identify ESC-equipped buses. Moreover, even if the buses could be identified, the number of cases in available crash data is not sufficient to evaluate the safety performance of the technology in its current stage of deployment, particularly given the low number of motorcoach crashes. In light of these limitations, all recent fatal motorcoach crashes were examined by using information from the accident reports, formal studies of the National Transportation Safety Board, and information in reconstruction reports to estimate the likelihood that the crash could have been prevented or mitigated had the motorcoach been fitted with functioning ESC technology. Results indicate that, if it is assumed that ESC had been fitted to all motorcoach buses, annual savings of $25 million could have been realized from loss-of-control and rollover crashes prevented. Even though the financial benefits for motorcoaches are limited because loss-of-control crash events are rare, the nonmonetary value of this technology is likely to exceed the financial benefits because motorcoaches transport the public and the reasonable expectation is that effective safety technology should be used even if the exposure is low. In particular, the risk of passenger casualties in a high-speed crash is much greater for a motorcoach than for other vehicles because of the large number of people on board.
Use of Powered Two-Wheelers in an Australian Capital City
Authors: Thompson Russell G. , Rose Geoffrey
Published: February 2014

Increasing concerns about traffic congestion, safety, availability of energy sources, and environmental issues such as pollution and climate change have led to growing interest in sustainable urban transport. Because these challenges have arisen from the rapid growth of motor vehicle ownership and use in urban areas, most of the focus has been on motorcars. In contrast, the role, use, and sustainability impacts of motor scooters and motorcycles—collectively called powered two-wheelers (PTWs)—have received relatively little attention from the transportation profession. Sales of PTWs in Australia have grown rapidly during the past decade, but little is known of their usage patterns. Insights into the trip and vehicle characteristics of PTWs observed in the central business district (CBD) of Melbourne, Victoria, Australia, are presented. An extensive patrol survey was undertaken in Melbourne's CBD to gain insight into the role of PTWs as a mode of transport. How a range of transport planning information can be gained by combining data from a large-scale observational survey with other data sets is illustrated. The parking patrol survey provided details of the accumulation and parking durations of PTWs on footpaths and in median parking areas. Combining the observational data with land use, registration, census, and public transport data allowed the development of relationships between trip generation, production, and journey distance. Such information has potential relevance in the context of developing policies related to the provision and pricing of PTW parking facilities as well as managing pedestrian areas in Melbourne's CBD.
Lessons Learned from Motorcyclist Surveys
Authors: Lee Chanyoung , Pino Joan , Choi Keechoo
Published: February 2014

Motorcycles are a means of transportation and one of the fastest-growing hobbies in the United States. Corresponding with a sharp increase in motorcycle registrations in Florida, motorcyclist fatalities and injuries have increased. It is well known that motorcycles are more than a mode of transportation to U.S. motorcyclists. Ownership of a certain motorcycle type is associated with social and behavioral characteristics that could affect how and why people ride motorcycles. Two surveys were conducted: one of motorcycle riders who had just completed the required motorcycle training to obtain their motorcycle endorsement and another of randomly selected Florida motorcyclists. The findings and lessons learned from these two surveys are summarized to gain insight into motorcyclist preferences and behaviors. Analysis with variance tests was performed to investigate the association between different variables, and a two-step cluster analysis was conducted to understand the use of safety helmets and respondents' attitudes toward the reinstatement of a universal helmet law in Florida. Results indicated that motorcyclists started riding for various reasons, but more young people tended to use a motorcycle as an inexpensive mode of transportation. In addition, 28.2% of respondents had never had formal motorcycle training. Most motorcyclists unanimously supported the mandatory training law, regardless of motorcycle type or rider age, gender, and riding experience. However, the riders had mixed opinions about reinstating a universal helmet law in Florida.
Logistic Regression Models of the Safety of Large Trucks
Authors: Qin Xiao , Wang Kai , Cutler Chase E.
Published: February 2014

Statistics show that crashes involving large trucks are generally more severe than those involving other vehicles because of the size, weight, and speed differential between trucks and other vehicles. Given the critical position of trucking in the process of economic recovery and growth, the improvement of truck safety and the mitigation of any negative impacts on non-truck vehicles are urgent issues. Statistical models have been used universally to identify the contributing factors to crash severities and to estimate injury probabilities. These methodologies, albeit addressing different issues, may provide mixed results and estimates with varying degrees of accuracy. The primary objective of this research was to investigate the effects of key determinants of the severity of crashes involving large trucks and to explore the relationship between the determinants. The secondary objective was to provide insight on statistical applications by evaluating three logistic regression models: multinomial logistic, partial proportional odds (PPO), and mixed logistic (ML) models. The model results showed that the majority of the coefficient estimates were consistent across the models studied. A few exceptions included young drivers and the use of safety constraints; these factors were not statistically significant in the ML model. The goodness of fit and model predictive power indicated that the PPO model produced results that more closely resembled the observations.