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...
Considering the deadly impacts of commercial motor vehicle (CMV) crashes on road safety, many previous studies have put in efforts to find the determinants of CMV crash injury severities. However, studies examining the impact of the different number of lanes on CMV crash
injury severities are lacking. Besides, the importance...
The outbreak of the Coronavirus Disease 2019 (COVID-19) and the restrictions implemented in response to it (e.g., stay-at-home orders, social distancing mandates, business closures) had unprecedented effects on the trucking industry. The pandemic prompted the first significant overhaul of federal hours-of-service (HOS) regulations in over 15 years. Prior to the...
Distracted driving is an adverse driving behavior that is widely known to impair the safety of all roadway users and traffic flow. Despite the extensive research efforts on the prevalence and effects of distracted driving on roadway safety and performance, the number of vehicular crashes and fatalities resulting from distracted...
The onset of the COVID-19 pandemic led to significant transformations in global mobility patterns, primarily driven by stay-at-home orders and economic shutdowns. These measures resulted in a substantial decline in travel activities worldwide. In the United States, there was a notable reduction in travel demand, with a corresponding decrease in...
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...
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...
While there have been several efforts to understand large-truck crashes, the relationship between crash factors, crash severity and collision type is not clearly understood. Past studies have utilized different statistical or econometric models to predict the manner of collision at intersections, yet not much attention has been paid to the...
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...
Large truck-involved crashes have a significant impact on both the economy and society. They are associated with high injury severities, high crash costs and contribute to congestion in urban areas. Past studies have investigated the contributing factors of large truck-involved crashes, however a study isolating the spatial and temporal effects...