Research News

A Data-Driven Safety and Operations Assessment of Various Left-Turn Phasing Strategies

Because drivers respond differently to different signal phasing sequences, engineers need to evaluate how drivers interpret the message that each phasing sequence is trying to convey. This research evaluated the safety and operational impacts of different left turn movement treatments at signalized intersections by using crash, video, and survey data. The results should help decision makers select more suitable signal phasing plans under various operational conditions.

Development of Surface-Mounted Smart Piezoelectric Modules for Bridge Damage Identification and Safety Monitoring

The goal of this study was to develop viable tools that utilize ultrasonic smart piezoelectric material (lead zirconate titanate, PZT) to assess the condition of concrete bridges. Existing non-destructive testing methods for inspecting concrete structures all suffer from limitations in accuracy, cost, maneuverability, in situ capability, and implementation. The researchers determined that the surface-mounted PZT system tested was effective in determining the wave modulus of elasticity of concrete structures and is a promising alternative nondestructive technique for assessing concrete properties.

Confounding Factors of Commercial Motor Vehicles in Safety Critical Events

When determining the causes of freight-related accidents, researchers need to disentangle the complex interactions among a range of causal and confounding factors, such as hours of service, time of day, traffic density, roadway type, environmental conditions, and driver behavior and characteristics. This study sought to uncover relationships between driver hours of service and a set of potential confounding factors related to time of day.

Safety Data Management and Analysis: Addressing the Continuing Education Needs for the Pacific Northwest (Phase 2)

Road safety is an evolving field, and preparing both students and practitioners with expertise in road safety is important. This project sought to respond to gaps in delivering transportation safety education and to develop introductory curriculum materials for both academicians and practitioners.

Evaluation of Motorcyclists’ and Bikers’ Safety on Wet Pavement Markings

Pavement markings such as single and double divider lines, edge lines, crosswalks, and bike lane markings are critical in guiding roadway users. However, pavement markings can also lead to catastrophic crashes for motorcyclists and bikers when they are wet or icy. This study evaluated three different pavement marking materials in dry, wet, and icy conditions, in the laboratory and in the field, to help improve rider safety.

Coordinated Incident and Congestion Management: Mitigating Impacts of Major Traffic Incidents in the Seattle I-5 Corridor

Within the Seattle major metropolitan area, multi-jurisdictional and coordinated traffic incident management (TIM) operations detect, respond to, and clear traffic incidents to restore traffic flow quickly and safely. However, there is a need to extend TIM operations to include congestion management (CM), which involves managing incident-generated congestion and mitigating regional impacts after an incident has been cleared. This project identified challenges and opportunities for enhancing regional TIM by including the management of major incidents along the Seattle I-5 corridor, supported by innovative technologies.

Mechanisms Involved in the Removal of Heavy Metals from Stormwater via Lignocellulosic Filtration Media

In the Pacific Northwest, elevated soluble zinc and copper concentrations originating from urban stormwater runoff pose a significant threat to native salmon and steelhead populations. In response to urbanization, existing stormwater infrastructure needs to be upgraded to treat non-point source pollution, including soluble metals, before they enter receiving waters. This project aimed to provide sustainable design suggestions for urban stormwater remediation at Washington State Ferry terminals. Researchers conducted laboratory and field-scale column tests to recommend specific types of plant filtration media for copper and zinc adsorption.

Recycled Glass Fiber Reinforced Polymer Composites Incorporated in Mortar for Improved Mechanical Performance

In this study, recycled glass fiber reinforced polymer composites from end-of-life wind turbine blades were evaluated as a replacement for sand in cement mortar. In the last two decades, glass-based materials in the form of powder or fibers from recycled bottles and other products, and more recently recycled glass fiber reinforced polymer (GFRP) composites from end-of-life products or industrial waste, have been incorporated into cement-based mixtures in various proof-of-concept designs. To understand better how GFRP would affect the properties of mortar, researchers conducted a feasibility study to compare different GFRP sizes and percentages.

Preliminary Procedure for the Structural Design of Pervious Concrete Pavements

The growing popularity of pervious concrete (PC) pavement applications has increased the need for establishing its mechanical properties and understanding their relationships with measurable properties for the purposes of designing layer thickness. In this project researchers developed multi-variable linear regression models to predict strength properties for pavement thickness design and developed a recommended thickness design database for low-traffic-volume PC pavements.

Developing Connections for Longitudinal Joints between Deck Bulb Tees—Development of UHPC Mixes with Local Materials

In past decades, many state departments of transportation and the Federal Highway Administration have begun working with ultra-high performance concrete (UHPC), an advanced cementitious material. WSDOT has not used UHPC in highway bridge applications, such as connection joints for precast concrete decks and girders, because of the concrete’s high cost and because of general lack of experience with it. The goal of this project was to develop a UHPC mixture using materials available locally and domestically as an alternative to commercially available, pre-packaged UHPC products.

Washington State Transportation Center