Engineering Commons^™

Understanding The Safety Impacts Of Left-Turn Infrastructure On The Vulnerable Driving Population, Francis Tainter

Doctoral Dissertations

The severe impact of roadway fatalities has remained a significant concern for researchers in recent years. As of 2015, traffic fatalities were the leading cause of death for individuals between the ages of 15 and 20 years old and a significant safety concern for drivers over the age of 65 years old (otherwise known as the “vulnerable” driving population). Intersection-related crashes have also remained prevalent in these demographic categories. Through four primary crash data evaluations, this dissertation explores the safety implications on the “vulnerable” driving population in the Commonwealth of Massachusetts. Through the utilization of newly developed crash data linkage …

All-Red Clearance Intervals For Use In The Left-Turn Application Of Flashing Yellow Arrows, Francis Tainter

Masters Theses

With the advancement of implementation for a novel traffic control device, the Flashing Yellow Arrow (FYA), agencies across the country have continually sought strategies to improve intersection operations and safety, specifically with respect to the left-turn application. More so, permissive left-turn intervals have been communicated to drivers using several traffic signal indications; however, most frequently these phases are represented through the circular green (CG) ball and more recently, the FYA. Previous research in this area determined that the FYA indication produced the most effective communication of permissive left-turns. Further, this previous research led to the inclusion of the FYA in …

An Evaluation Of Traffic Control Devices And Driver Distraction On Driver Behavior At Railway-Highway Grade Crossings, Radhameris A. Gomez Gabriel

Doctoral Dissertations

At-grade crossings (grade crossings) are those crossings in which any part of a roadway intersects with railroad tracks. Safety at these railroad-highway grade crossings is a major concern, with traffic control warning devices serving as the main mechanisms for improving safety. There are three factors that influence a driver’s behavior at a given crossing. First, traffic control devices, including warning devices at the railroad-highway grade crossings, provide the driver with information whose impact will depend in part on the likelihood that the driver knows whether to glance in the direction of the device based on prior experience, and in part …

Evaluating The Impacts Of Driver Behavior In The Speed Selection Process And The Related Outcomes, Cole D. Fitzpatrick

Doctoral Dissertations

In the United States, traffic crashes claim the lives of 30,000 people every year and is the leading cause of death for 5-24 year olds. Driver error is the leading factor in over 90 percent of motor vehicle crashes, with the roadway and the vehicle each only accounting for about 2 percent of crashes. In the United States, nearly a third of fatal crashes are due to speeding and therefore, a critical step in improving traffic safety is research aimed to reduce speeding, such as crash data analysis, outreach campaigns, targeted enforcement, and understanding speed selection. In this dissertation, a …

A Quantitative Analysis Of The Impacts From Selected Climate Variables Upon Traffic Safety In Massachusetts, Katrina M. Hecimovic

Masters Theses 1911 - February 2014

Current literature predicts that climate change may increase both the occurrence and severity of heavy rainfall events and winter precipitation in the Northeast United States. A potential increase in intense precipitation events related to climate change would theoretically also cause an increase in weather-related delays, increase in overall traffic disruptions, a substantive shift in travel behavior, and presumably a negative effect on safety and maintenance operations of highways. This current research study examines the existing impacts from both an operational and behavioral perspective of how weather events currently impact overall safety along routes in Massachusetts. A secondary objective of the …

An Application Of Spatially Based Crash Analyses And Road Safety Investigations To Increase Older Driver Safety, Deanna A. Peabody

Masters Theses 1911 - February 2014

Arguably the greatest issue facing the transportation profession is the ability to provide social equity with regards to both safety and mobility given the aging population. Given the overall dominance of the automobile within the transportation system, the ability to provide feasible alternatives is daunting. This fact, when coupled with the well-documented challenges of older drivers, underscores the need for improved safety features and system-wide safety approaches with a focus on the older driver. This paper describes an application of spatial crash analysis and road safety investigations that were employed in Massachusetts with a direct focus on the older driver. …

Safety And Operational Assessment Of Gap Acceptance Through Large-Scale Field Evaluation, Steven Maxwell Tupper

Masters Theses 1911 - February 2014

Given that “driver error” is cited as a contributing factor in 93 percent of all crashes, understanding driver behavior is an essential element in mitigating the crash problem. Among the more dangerous roadway elements are unsignalized intersections where drivers’ gap acceptance behavior is strongly correlated to the operational and safety performance of the intersection. While a basic understanding of drivers’ gap acceptance behavior exists, several unanswered questions remain.

Previous work has attempted to address some of these questions, however to date the research has been somewhat limited in scope and scale due to the challenges of collecting high fidelity gap …

Application Of Driver Behavior And Comprehension To Dilemma Zone Definition And Evaluation, David S. Hurwitz

Open Access Dissertations

Among the most critical elements at signalized intersections are the design of vehicle detection equipment and the timing of change and clearance intervals. Improperly timed clearance intervals or improperly placed detection equipment can potentially place drivers in a Type I dilemma zone, where approaching motorists can neither proceed through the intersection before opposing traffic is released nor safely stop in advance of the stop bar. Type II dilemma zones are not necessarily tied to failures in design, but are more readily tied to difficulties in driver decision making associated with comprehension and behavior. The Type II dilemma zone issues become …