Most specifications for ready-mix concrete (RMC) limit mixing time to 90 minutes and/or truck drum revolution counts (DRC) to 300 before discharge. These specifications have been in place for many years with the objective of ensuring the quality and performance of the finished concrete product. However, limited research has been...
Highway capacity has traditionally been treated as deterministic. In reality, however, capacity can vary from time to time and location to location due to inclement weather, various driving behavior, traffic incident, bottleneck and workzone. This thesis aims to characterize the stochastic variations of highway capacity, and explore its applications.
The...
A right-hook crash is a bicycle-motor vehicle crash between a right-turning motor vehicle and an adjacent through-moving bicycle. This study focuses on right-hook crashes that occur during the latter stage of the circular green indication at signalized intersections with shared right-turn and through lanes. The overall objective was to evaluate...
This thesis provides a comparison of advanced econometric frameworks to account for unobserved factors in crash reported data (also referred to as unobserved heterogeneity) while identifying contributing factors by roadway classification for heavy vehicle injury severity and crash rates. The presented thesis provides two manuscripts that expand the literature regarding...
Flexible pavements consist of multilayers, which form the pavement structures. Since the strength of the bond at interface between layers plays a significant role in improving the structural integri-ty and the performance of pavement structures, tack coat materials and methods used for their application during construction are important in providing...
CSS-1H is the most commonly used slow-setting emulsion grade in Oregon. “New” engineered emulsions were recently developed in Oregon to reduce tracking, the pick-up of tack coats by construction vehicle tires during construction activities, and increase interlayer shear strength (ISS), the amount of adhesive bond present between layers of asphalt...
Concrete is the most widely used construction material in the world. When constructing large concrete structures, concrete may have to be placed in multiple lifts. In these cases, fresh concrete is placed on hardened concrete. The interface that is formed between these two lifts of concrete is known as a...
Wheeled mobility devices (WhMD) pose unique safety risks to users while riding public transportation. Unsecured or improperly secured WhMDs create safety concerns for other transit riders and operators. Tests using accelerometers and visual observations were conducted to understand how WhMD orientation and securement in articulated buses, streetcars, and light rail...
Red Light Running (RLR) is a safety hazard at signalized intersections in Oregon and throughout the United States. Various methods of mitigating factors contributing to RLR have been implemented but few protect against a conflict when a vehicles runs a red light. Additionally, current prediction algorithms are complicated; there is...
Pedestrian distraction at roadway crossings has been correlated with a higher risk of pedestrian-vehicle collisions due to the pedestrian's cognitive, visual, and motor attention being drawn to a wide variety of secondary tasks.
This study is different from previous field studies of pedestrian midblock crossings in that the geometric layout...
High Performance Concrete (HPC) is used in our crucial pieces of infrastructure, such as bridge decks, due to its enhanced durability and engineering properties. However, HPC is highly susceptible to early-age cracking. Cracking within the first months of a bridge deck’s lifespan can severely hinder its long-term performance and durability....
Short-term freeway traffic speed prediction is essential to improving mobility and safety. It has been a challenging, yet unresolved issue. Traffic speed prediction can be applied to enhance the intelligent freeway traffic management and control for applications as operational and regulation planning. For example, with more reliable traffic speed prediction,...
Highway construction projects require temporary changes in roadway characteristics, such as the number of operational lanes, lane path, lane width, shoulder width, and posted speed limit. These modifications which are often temporary in nature have the potential to impact driving performance. Many research efforts have focused on developing standards to...
Moisture damage has long been recognized as one of the most
critical factors influencing the performance of asphalt concrete (AC)
pavements. This moistureinduced damage occurs from either the
physical separation of the asphalt film from the aggregate or the
softening of the asphalt binder within the AC mixture in the...
The inclusion of students with disabilities in general physical education (GPE) classes has become a concept and practice that is expected if not always understood. A review of inclusion in physical education literature suggested that GPE teachers possess less than favorable feelings towards the inclusion of students with disabilities in...
Asynthesis & Act is a significant intervention into the discourse of the sublime. Through a deep investigation of the critical metaphysics of Immanuel Kant, the first chapter of this thesis puts forth the claim that the sublime is a radical experience that occasions a possibility for the individual to commit...
During the 2006/07 academic year, 582,984 international students studied in the United States (Open Doors Study, 2007). Roughly 430,000 of these international students were pursuing Bachelors or Graduate level degrees. Of the international students that complete degrees, most will return to their home country and will be unable to attend...
Crash rates are said to be nearly three times higher on curved sections than those on straight sections of rural roadways. As a result, advisory curve/speed signs are standard practice to mitigate these risks on sharp horizontal curves. The industry standard for determining appropriate and uniform speeds for such signs...
The rapid growth in the number of roundabouts raises some significant research challenges, especially around safety performance and evaluation in the U.S. Despite the safety advantages that roundabout geometric design brings, crashes still occur. While operationally roundabouts are good at preventing severe crashes, they may lead to more less severe...
With ever-increasing number of vehicles actively using the state and national roadway network, transportation-related fuel consumption and consequent pavement structural damage rises. In this dissertation, the impact of material-induced dissipated energy mechanisms in asphalt and concrete pavements were analyzed using field measurements in California and finite element modeling of pavement...