UMD Theses and Dissertations
Permanent URI for this collectionhttp://hdl.handle.net/1903/3
New submissions to the thesis/dissertation collections are added automatically as they are received from the Graduate School. Currently, the Graduate School deposits all theses and dissertations from a given semester after the official graduation date. This means that there may be up to a 4 month delay in the appearance of a given thesis/dissertation in DRUM.
More information is available at Theses and Dissertations at University of Maryland Libraries.
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Item DEVELOPMENT OF A MIXED-FLOW OPTIMIZATION SYSTEM FOR EMERGENCY EVACUATION IN URBAN NETWORKS(2012) Zhang, Xin; Chang, Gang-len; Civil Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)In most metropolitan areas, an emergency evacuation may demand a potentially large number of evacuees to use transit systems or to walk over some distance to access their passenger cars. In the process of approaching designated pick-up points for evacuation, the massive number of pedestrians often incurs tremendous burden to vehicles in the roadway network. Hence, one critical issue in a multi-modal evacuation planning is the effective coordination of the vehicle and pedestrian flows by considering their complex interactions. The purpose of this research is to develop an integrated system that is capable of generating the optimal evacuation plan and reflecting the real-world network traffic conditions caused by the conflicts of these two types of flows. The first part of this research is an integer programming model designed to optimize the control plans for massive mixed pedestrian-vehicle flows within the evacuation zone. The proposed model, integrating the pedestrian and vehicle networks, can effectively account for their potential conflicts during the evacuation. The model can generate the optimal routing strategies to guide evacuees moving toward either their pick-up locations or parking areas and can also produce a responsive plan to accommodate the massive pedestrian movements. The second part of this research is a mixed-flow simulation tool that can capture the conflicts between pedestrians, between vehicles, and between pedestrians and vehicles in an evacuation network. The core logic of this simulation model is the Mixed-Cellular Automata (MCA) concept, which, with some embedded components, offers a realistic mechanism to reflect the competing and conflicting interactions between vehicle and pedestrian flows. This study is expected to yield the following contributions * Design of an effective framework for planning a multi-modal evacuation within metropolitan areas; * Development of an integrated mixed-flow optimization model that can overcome various modeling and computing difficulties in capturing the mixed-flow dynamics in urban network evacuation; * Construction and calibration of a new mixed-flow simulation model, based on the Cellular Automaton concept, to reflect various conflicting patterns between vehicle and pedestrian flows in an evacuation network.Item An Analysis of Pedestrian-Vehicular Crashes Near Public Schools in the City of Baltimore, Maryland(2005-05-04) Fults, Kandice Kreamer; Clifton, Kelly J; Civil Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)In previous research, children have been shown to be involved in pedestrian-vehicular crashes in high numbers due to improper pedestrian behaviors. Little research has been conducted to examine the relationship between schools and pedestrian crashes. This study analyzes pedestrian-vehicular crashes in the City of Baltimore, Maryland to determine any relationships that may exist between crashes near public schools and the physical and social attributes of these schools. It was found that the presence of a driveway decreases crash occurrence and severity. A setback from the road will decrease crash occurrence but increase the severity of the crashes. The presence of off-street parking was shown to increase the severity of a crash, particularly for children ages 16-18. Recreational facilities are shown to increase the crash occurrence and severity of crashes. This study however, is limited as it does not include pedestrian demand data and the results should be interpreted as such.Item Pedestrian-Vehicular Crashes: The Influence of Personal and Environmental Factors(2005-05-03) Burnier, Carolina Valdemarin; Clifton, Kelly J; Civil Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)This thesis examines the relationship between land use and pedestrian-vehicle crashes. Analysis focuses on how the pedestrian crashes vary by personal characteristics (age, sex, condition, and severity of injury) and physical characteristics of the crash area (location type, population density, land use, pedestrian activity, and demand). The data for this study are pedestrian- vehicle crashes in Baltimore City, MD occurring between 2000 and 2002, supplied by the State of Maryland Motor Vehicle Accident Report. The results from the analysis suggest that in general, there are significant effects of land use on pedestrian crashes and, more importantly, pedestrian exposure. When controlling for demand, urban downtown areas with high population and roadway densities and good commercial accessibility are found to have negative relationships to pedestrian exposure. The results may justify the promoting of denser urban neighborhood designs and advocate the need to guide safety policy investments to these urban areas with high pedestrian activity.