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...
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...
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...
This dissertation provides a comparison of statistical and econometric frameworks, using a previously unused freight data source, to study crash frequency by crash type and heavy-vehicle hard braking in Oregon. Hard braking can serve as a proxy for several factors, one of which is safety. Therefore, with the hard braking...
Recent statistics regarding large truck crashes reveal that fatality rates of large trucks per 100 million vehicle miles traveled (VMT) and fatality rates per 1,000 registered vehicles are higher than those for passenger vehicles. These statistics underscore the need for greater efforts by safety professionals to help mitigate the impacts...
The production of cement and concrete results in the production of large amounts of CO₂ emissions which can have significant negative environmental impacts. Using supplementary cementing materials (SCMs) as a cement replacement is an effective solution to reduce these negative environmental impacts, as most SCMs are waste by-products from other...
Low temperature cracking is attributed to tensile stresses induced in an
asphalt concrete pavement that develop when the pavement is subjected to a cold
temperature. Cracking results in poor ride quality and a reduction in service life of
the pavement. Low temperature cracking has been predicted by regression
equations, mechanistic...
The number of international inbound tourists to the United States has risen steadily. To serve these and other tourists best, traffic signs need to communicate information correctly across a potential language barrier. Of particular interest is the traffic sign intended to communicate directions to Tourist Information centers. While the general...
Thermal distress in asphalt concrete pavements is a widespread problem around
the world. Thermal cracking can be divided into two modes of distress: low
temperature cracking and thermal fatigue cracking. Low temperature cracking results
from extremely cold temperatures; thermal fatigue cracking results from daily
temperature cycles.
Low temperature cracking is...
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...
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...
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...
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...
Asphalt concrete fatigue cracking is recognized as a major distress mode in the U.S. The widespread nature of this distress and the data from agency Pavement Management Systems (PMS) suggest that it is an issue with asphalt mixture design and production processes and is not a problem specific to certain...
Due to a general reduction in pavement program funding levels over the past decade, the current budget is not sufficient to maintain roadways at a high level of service with acceptable roughness levels. Rough roadways with poor ride quality increase drivers’ vehicle operating costs (fuel consumption, vehicle maintenance, and tire-wear)...
The collapse of the I-35W Bridge in Minneapolis, MN in 2007 prompted an investigation into the design and inspection of the steel truss bridges. Further investigation into the collapse revealed that a gusset plate experienced sway buckling, causing the bridge failure. This bridge failure motivated research into the analysis and...
We are witnessing the rise of the data-driven science paradigm, in which massive amounts of data - much of it collected as a side-effect of ordinary human activity - can be analyzed to make sense of the data and to make useful predictions. To fully realize the promise of this...
This study involved the determination of the structural layer properties of
aggregate and asphalt surfaced pavements for use in the evaluation of pavement load
carrying capacity and the seasonal effects of moisture. This was achieved by the use
of Nondestructive Testing Methods (NDT) and backcalculation techniques. Pavement
surface deflection measurements...
Environmental factors such as temperature, air, and water can have a profound
effect on the durability of asphalt concrete mixtures. In mild climates where good
quality aggregates and asphalt cement are available, the major contribution to
deterioration may be due to traffic loading and the resultant distress is manifested
in...
Wheat (Triticum aestivum) is a globally traded staple food crop. The diverse and pleasing nature of wheat-derived products is a result of the complex interactions of the polymeric components from the wheat endosperm. Changes in the functionality of these polymeric components, as a result of changes in growing conditions or...
In response to the growing environmental concern and higher operating cost of regular automobile, the concept of Low-Speed Vehicles (LSVs) is becoming popular as a sustainable mode of transportation. Primarily designed for protected environments and gated communities, the use of these vehicles is gradually increasing on public roadways as a...
This thesis documents the evaluation of the initial performance of pavement
containing recycled asphalt shingles (RAS) in Oregon. The research was funded
by the Oregon Department of Transportation (ODOT) and the Federal Highway
Administration and was conducted at Oregon State University. The key
objectives of this thesis are to document...
This thesis evaluates pre-construction auditing procedures used in the United Kingdom, Australia, and New Zealand in order to help create post-construction auditing procedures for the state of Oregon. It was funded as part of the development of the Oregon Department of Transportation (ODOT) Safety Investigation Manual, and also evaluates content...
In the vicinity of the pseudocritical point, supercritical carbon dioxide (sCO₂) undergoes a steep change in properties from “liquid-like” to “gas-like” as it is heated at a constant pressure. At the same time, there is a large spike in specific heat which can yield high heat transfer coefficients and heat...
The resistance of asphalt concrete pavement to distresses such as fatigue cracking and permanent deformation is governed by how well the structure can resist loading under a variety of traffic and climate-related conditions. Asphalt binder type and content are typically the variables that pavement engineers can manipulate to render the...
Wheat is a globally traded staple crop. Wheat is important in human diets because of its agronomic adaptability, physical characteristics, functionality for the production of leavened products and nutritional value. Two significant characteristics make wheat an important staple food-crop. First, the proteins present in wheat endosperm have attributes that enable...
Operating speed is one of the best performance measures that can tell transportation agencies how well or how poorly the transportation system is functioning. Fluctuating operating speeds often mean there is a design flaw or something about the physical road design that violates drivers' expectations. A primary example of this...
Public housing (PH) provides a substantial portion of the housing in both developed and less developed countries, and the demand for it is increasing. The PH projects, however, are facing many challenges that are affecting their performance and cause their failures. The United States has demolished large portions of their...
The purpose of this work is to broaden the theoretical foundations of interpolation of spatial data, by showing how ideas and methods from information theory and signal processing are applicable to the the work of geographers. Attention is drawn to the distinction between what we study and how we represent...
Hemlock dwarf mistletoe (Arceuthobium tsugense subsp. tsugense) is an arboreal, hemiparasitic plant that principally parasitizes western hemlock (Tsuga heterophylla). Hemlock dwarf mistletoe exerts a profound influence on infected trees that can drastically change the structure of the tree crown due to reduced growth, top dieback, branch deformation and death, resulting...
The accelerated development in water-energy systems calls for advanced modeling and optimization tools to improve technologies’ performance. Water desalination is a manifestation of water-energy system that is challenged by different operational constraints. The scarcity and uneven distribution of freshwater around the world makes water desalination an indispensable process to address...
The hermit thrush (Catharus guttatus) and the varied thrush (Ixoreus naevius) are focal species for conservation of forested habitats in Oregon. Although habitat associations have been defined for both species, their response to changes in vegetation following wildfire has not been well studied. To help fill this information gap, I...
Oceanic uptake of rising anthropogenic CO₂ emissions has caused the emergence of ocean acidification as a major threat to marine ecosystems worldwide. Along eastern boundary current systems, seawater is naturally acidified due to coastal upwelling of low pH seawater from depth. Compounded by ocean acidification, upwelling regions are expected to...
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Bruce A. Menge
Oceanic uptake of rising anthropogenic CO2 emissions has caused the
Descriptions of the fire regime in the Douglas-fir/western hemlock region of the Pacific Northwest traditionally have emphasized infrequent, predominantly stand-replacement fires and an associated linear pathway of stand development, where all stands proceed along a common pathway until reset by the next fire. Although such a description may apply in...
There are over 35 known virus and virus-like diseases of sweet cherry (Prunus avium), some with potential to cause severe economic impact by reducing vegetative growth, vigor, and/or quality of fruit. Oregon is the second-ranked state for sweet cherry production in the United States with 13,000 acres and $70.8 million...
Two distinct strategies were explored for the enantioselective synthesis of α-heteroatom substituted alkyl boronic esters by stereoselective reagent-controlled homologation using transient chiral carbenoid reagents CHYMX (Y = heteroatom, X = nucleofuge, M = electrofuge). In the first case, a stereospecific reagent-controlled homologation (sStReCH) approach to α-alkoxyalkylboronates using α-metalated S,O- and...
The phytopathogen Phytophthora ramorum (Werres, DeCock & Man in't Veld), causal agent of Sudden Oak Death (SOD) of oaks (Quercus spp.) and tanoaks (Notholithocarpus densiflorus syn. Lithocarpus densiflorus), is established in coastal forests of the western United States. Since the discovery of SOD in the Douglas-fir / tanoak forests of...