Announcing the Final Examination of Nafis Anwari for the degree of Doctor of Philosophy
This dissertation has contributed to the pedestrian safety literature by assessing and comparing safety benefits and traffic efficiency among midblock Rectangular Rapid Flashing Beacon (RRFB) and Pedestrian Hybrid Beacon (PHB) sites. Video trajectory data were used to calculate pedestrian Surrogate Safety Measures (SSMs) and vehicles' delay. Univariate and multivariate regression of SSMs and vehicles' delay revealed that PHB sites offer more safety benefits, at the expense of increased vehicles' delay, compared to RRFB sites. The presence of the PHB, weekday, signal activation, lane count, pedestrian speed, vehicle speed, land use mix, traffic flow, time of day, and pedestrian starting position from the sidewalk have been found to be significant determinants of the SSMs and vehicles' delay. The findings of this study pave the way for practitioners and policymakers to evaluate the effectiveness of midblock pedestrian crossing facilities. Another avenue of pedestrian safety explored in this dissertation is the lag time. Lag time of a pedestrian is the time passed after a crash has occurred until the pedestrian died. The study investigates survival likelihood and the lag time of non-instant pedestrian fatalities using a random parameter binary logit and ordered logit models. The models were run on a dataset obtained from the Fatality Accident Reporting System for the period of 2015-2019. The analysis revealed that Weather, Driver age groups, Drunk/ distracted/ drowsy drivers, Hit and Run, Involvement of Large Truck, VRU age group, gender, Presence of Sidewalk, Presence of Intersection, Light Condition, and Speeding were common significant factors for both models. The results validate the use of lag time as an alternative to crash count and crash severity analysis. The findings of this study pave the way for practitioners and policymakers to use lag time to investigate crashes and corroborate results from traditional crash-based investigations
Committee in Charge:
Mohamed Abdel—Aty, Chair, Department of Civil, Environmental and Construction Engineering
Naveen Eluru, Department of Civil, Environmental and Construction Engineering
Samiul Hasan, Department of Civil, Environmental and Construction Engineering
Zubayer Islam, Department of Civil, Environmental and Construction Engineering
Xin Yan, Department of Statistics & Data Science