Static and Dynamic Evaluation of the Driver Speed Perception and Selection Process

Speed impacts the extent to which mobility and safety are experienced across the surface transportation network. By expanding current understanding of speed perception and selection processes our ability to understand and comprehensively address speed-related issues will improve. Driving simulator technology has advanced the field of transportation research. However, it has been limited in its application to speed-related issues. Furthermore, static computer-based evaluations have been used as a means of establishing a preliminary understanding for driver interpretation of stimuli encountered in the roadway, but have been limited in their application to speed. These technologies allow for large sample populations to be evaluated quickly and safely. Phase I of this initiative examined driver ability to perceive travel speeds in a similar real world, simulated world, and static environment. The experimental course traversed roadway where land-use and posted speed limits varied. Drivers’ actual and perceived speeds were recorded at 20 identical “checkpoint” locations in each environment, and the results were analyzed across drivers and environments. Phase II examined three roadway attributes that impact the speed-selection process. A focus group was employed to build improved scenarios of interest for a full-scale static evaluation. In the static environment, 75 drivers were asked how fast they would travel while individual characteristics of the scenario displayed were modified. This multifaceted research initiative expands the potential application of advanced technology in speed-related research, and improves the understanding of factors that influence speed perception and selection processes

Driver and Bicyclist Comprehension of Blue Light Detection Confirmation Systems

This study analyzed motorist and bicyclist understanding and preference of positive confirmation of detection of a bicycle by the traffic signal infrastructure using a blue light detection confirmation (BLDC). The research analyzed results of an online survey of 1,123 respondents and intercept survey of 337 respondents. The study initially found that participants of the survey did not understand the meaning of the blue light itself, but comprehension of the system rose from 40% to 50% when supplemental signs were used. Respondents overwhelmingly indicated that they preferred the sign option that included symbols, text, and a representation of the blue light, in comparison with the sign options that only included symbol and text, or text and blue dot. Additionally, respondents indicated that they “strongly agree” that the supplemental signage helped with understanding the purpose of the detection confirmation devices, that they would support the system at intersections, and that it made them feel better about waiting at an intersection with light. Including supplemental signage with the symbol, text, and blue dot could potentially improve the riding experience for users, as it was strongly preferred among the alternative sign options that were tested; however, further evaluation of sign configurations may be warranted

Fuzzy Logic for Improved Dilemma Zone Identification: A Driving Simulator Study

Type-II dilemma zones are the segment of roadway approaching an intersection where drivers have difficulty deciding to stop or proceed at the onset of the circular yellow (CY) indication. Signalized intersection safety is improved when dilemma zones are correctly identified and steps are taken to reduce the likelihood that vehicles are caught in such zones. This research purports that using driving simulators as a means to collect driver response data at the onset of the CY indication is a valid methodology to augment our analysis of decisions and reactions made within the dilemma zone. The data obtained was compared against that from previous experiments documented in the literature and the evidence suggests that driving simulation is valid for describing driver behavior under the given conditions. After validating the data, fuzzy logic was proposed as a tool to model driver behavior in the dilemma zone, and three models were developed to describe driver behavior as it relates to the speed and position of the vehicle. These models were shown to be consistent with previous research on this subject and were able to predict driver behavior with up to 90% accuracy

Driver Response to Phase Termination at Signalized Intersections at Signalized Intersections: Are Driving Simulator Results Valid?

Type-II dilemma zones are the segment of roadway approaching an intersection where drivers have difficulty deciding to stop or proceed at the onset of the circular yellow indication. Signalized intersection safety is improved when dilemma zones are correctly identified and steps are taken to reduce the likelihood that vehicles are caught in such zones. This research purports that using driving simulator as a means to collect driver response data at the onset of the circular yellow indication is a valid methodology to augment our analysis of decisions and reactions made within the dilemma zone. The data obtained was compared against that from previous experiments documented in the literature and the evidence suggests that driving simulation is a valid mechanism for describing driver behavior under the given conditions

Backing collisions: a study of drivers\u27 eye and backing behaviour using combined rear-view camera and sensor systems

Context—Backing crash injures can be severe; approximately 200 of the 2,500 reported injuries of this type per year to children under the age of 15 years result in death. Technology for assisting drivers when backing has limited success in preventing backing crashes. Objectives—Two questions are addressed: Why is the reduction in backing crashes moderate when rear-view cameras are deployed? Could rear-view cameras augment sensor systems? Design—46 drivers (36 experimental, 10 control) completed 16 parking trials over 2 days (eight trials per day). Experimental participants were provided with a sensor camera system, controls were not. Three crash scenarios were introduced. Setting—Parking facility at UMass Amherst, USA. Subjects—46 drivers (33 men, 13 women) average age 29 years, who were Massachusetts residents licensed within the USA for an average of 9.3 years. Interventions—Vehicles equipped with a rear-view camera and sensor system-based parking aid. Main Outcome Measures—Subject’s eye fixations while driving and researcher’s observation of collision with objects during backing. Results—Only 20% of drivers looked at the rear-view camera before backing, and 88% of those did not crash. Of those who did not look at the rear-view camera before backing, 46% looked after the sensor warned the driver. Conclusions—This study indicates that drivers not only attend to an audible warning, but will look at a rear-view camera if available. Evidence suggests that when used appropriately, rear-view cameras can mitigate the occurrence of backing crashes, particularly when paired with an appropriate sensor system

Traffic Signal System Misconceptions Across Three Cohorts: Novice Students, Expert Students, and Practicing Engineers

Theories of situated knowledge and research evidence suggest that students are not prepared for the engineering workforce upon graduation from engineering programs. Concept inventory results from diverse fields suggest that students do not understand fundamental engineering, mathematics, and science concepts. These two concerns may result from different knowledge deficiencies; one from lack of conceptual understanding and the other from lack of applied knowledge. The research goals of this paper are to identify misconceptions, knowledge about phenomena that are persistent and incorrect, related to traffic signal operations and design in novice and expert engineering students and practicing engineering and to attempt to explain the patterns in misconceptions across these three cohorts. Results indicate three patterns (decreasing, increasing, and no change) of misconceptions across the three cohorts considered in this study (novice students, expert students, and practicing engineers). The pattern of decreasing misconception can be explained by a traditional model of learning that suggests improved understanding with additional instruction and student time on task. The pattern of increasing misconception appeared for concepts that were particularly complex and confounded, where practicing engineers produced much more complex answers that were mostly correct, but made leaps and speculations not yet proven in the literature. Misconception frequencies that stayed the same tended to include topics that do not have required national standards or that are buried in automated processes. The process of identifying and documenting misconceptions that exist across these cohorts is a necessary step in the development of data driven curriculum. An example of a conceptual exercise developed from four misconceptions identified in this study is also demonstrated

Deletion of vascular endothelial growth factor in myeloid cells accelerates tumorigenesis.

Angiogenesis and the development of a vascular network are required for tumour progression, and they involve the release of angiogenic factors, including vascular endothelial growth factor (VEGF-A), from both malignant and stromal cell types. Infiltration by cells of the myeloid lineage is a hallmark of many tumours, and in many cases the macrophages in these infiltrates express VEGF-A. Here we show that the deletion of inflammatory-cell-derived VEGF-A attenuates the formation of a typical high-density vessel network, thus blocking the angiogenic switch in solid tumours in mice. Vasculature in tumours lacking myeloid-cell-derived VEGF-A was less tortuous, with increased pericyte coverage and decreased vessel length, indicating vascular normalization. In addition, loss of myeloid-derived VEGF-A decreases the phosphorylation of VEGF receptor 2 (VEGFR2) in tumours, even though overall VEGF-A levels in the tumours are unaffected. However, deletion of myeloid-cell VEGF-A resulted in an accelerated tumour progression in multiple subcutaneous isograft models and an autochthonous transgenic model of mammary tumorigenesis, with less overall tumour cell death and decreased tumour hypoxia. Furthermore, loss of myeloid-cell VEGF-A increased the susceptibility of tumours to chemotherapeutic cytotoxicity. This shows that myeloid-derived VEGF-A is essential for the tumorigenic alteration of vasculature and signalling to VEGFR2, and that these changes act to retard, not promote, tumour progression

Celebrating 20 Years of the ExCEEd Teaching Workshop

In response to the clear need for faculty training, the American Society of Civil Engineers (ASCE) developed and funded Project ExCEEd (Excellence in Civil Engineering Education) which is celebrating its twentieth year of existence. For the past two decades, 38 ExCEEd Teaching Workshops (ETW) have been held at six different universities. The program has 910 graduates from over 267 different U.S. and international colleges and universities. The ExCEEd effort has transformed from one that relied on the grass roots support of its participants to one that is supported and embraced by department heads and deans. This paper summarizes the history of Project ExCEEd, describes the content of the ETW, assesses its effectiveness, highlights changes in the program as a result of the assessment, and outlines the future direction of the program

Assessment of the Introductory Transportation Engineering Course and the General Transportation Engineering Curriculum

Transportation engineering is a critical subdiscipline of the civil engineering profession as indicated by its inclusion on the Fundamentals of Engineering Examination, its overlap with other specialty areas of civil engineering, and as recognized by the Transportation Research Board, Institute of Transportation Engineers, and the American Society of Civil Engineers. With increasing transportation workforce needs, low numbers of students entering the ‘pipeline’, and limited hours within undergraduate civil engineering programs, it is important to ensure civil engineering students receive adequate preparation and exposure to career opportunities in the transportation engineering field. As such, investigations into the status of transportation engineering within civil engineering programs and specifically the introductory transportation engineering course are essential for understanding the implications to the profession. This paper presents a review of relevant literature and findings from a new survey of ABET-accredited civil engineering programs that yielded 84 responses. The survey indicates that 88 percent of responding programs teach an introductory course in transportation engineering, and 79 percent require it in their undergraduate programs. There is significant variation in the structure of the introductory course (number of credit hours, lab requirements, etc.), and common responses regarding improvements that could be made include adding labs, requiring a second course, and broadening course content. In addition, nearly 15 percent of instructors teaching the introductory course did not have a primary focus in transportation engineering. This finding should be investigated further, given that this course may be an undergraduate civil engineering student’s only exposure to the profession.This is an author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by the Transportation Research Board of the National Academies and can be found at: https://doi.org/10.3141/2328-0

Improved Safety and Efficiency of Protected/Permitted Right Turns for Bicycles in the Pacific Northwest

DTRT13-G-UTC40Conflict between bicycles and right-turning vehicles on the approaches to intersections is a critical safety concern in urban environments. To understand the safety and operational implications of using protected-permitted right turns (PPRT), a full-scale bicycling simulator experiment was performed. The velocity and lateral position of bicyclists were evaluated during conflicts between bicycles and right-turning vehicles. Two independent variables were analyzed: the signal indication for right-turning vehicles (circular red or green, solid red or green arrow and flashing yellow arrow) and the pavement markings in the conflict area (white lane markings with no supplemental pavement color and white lane markings with solid green pavement applied in the conflict area). Forty-eight participants (24 women and 24 men) completed the experiment. Signal indications and pavement markings had statistically significant effects on bicycle velocity and lateral position, but these effects varied at different levels of the independent variables. Use of PPRT phasing in conjunction with colored pavement markings was associated with increased bicyclist conflict with right-turning vehicles, whereas PPRT phasing with no supplemental colored pavement markings was associated with improved bicyclist safety. The results provide guidance to transportation professionals about how traffic control devices could be applied to conflict areas before signalized intersections