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...
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...
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...
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...
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...
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...