Thesis (Ph. D.)--University of Wisconsin--Madison, 1980. / Typescript. Vita. Includes bibliographical references (leaves 511-545b).

<p> Transportation planning is a vital and necessary operation for a metropolitan area to grow. As such, and in order to receive Federal funding for transportation projects, metropolitan areas engage in transportation planning as regulated by MAP-21. One element of meeting MAP-21 requirements is addressing the safety of a region. With new requirements by MAP-21, MPOs must demonstrate some sort of performance measure showing changes in the various elements, making quantitative means of displaying these changes ever more important. </p><p> The goal of this project was to develop a model or set of models that could produce quantitative results as opposed to the traditional qualitative results gained from professional opinion. This allows for better decision-making for test project scoring in transportation plans and additionally in meeting MAP-21 requirements. Following a review of the current available methodologies and an inventory of other states&rsquo; efforts to develop crash prediction models, mathematical modeling for Louisiana statewide crash prediction formulae were attempted. These results and the methodology were deemed unsuitable for the desired outcomes and the use of SVR modeling was explored. </p><p> The use of the SVR models described in this report produce acceptable results, have been validated for use in forecasting, and allow for the comparison of conditions between base data, future years, and future years with MTP test projects included. The results of these models provide transportation planners increased means to determine project rankings based on safety as well as satisfy MAP-21 requirements.</p>

Relationships between highway improvements in the Southwestern U.S., as measured by changing accessibility of selected cities, and population were measured over the period 1920-90. Few significant relationships were found using a distance-based measure of accessibility, but the inclusion of proximity to population resulted in much stronger relationships. Despite this, little or no directionality in these relationships was evident, and the results do not support the hypothesis of a regional highway orientation toward urban population. Similar testing between traffic flows over selected routes and highway improvements, though resulting in close relationships. were similarly lacking in directionality and failed to provide a better explanation of the spatial pattern of Southwestern highway improvements.

No description available.

The accident situation in Great Britain is reviewed, and the process of gap acceptance is described. Studies of gap acceptance behaviour at intersections are discussed according to the factors which were investigated, and some of the literature on pedestrian gap acceptance is reviewed. The use of the traffic conflicts technique in this country is also outlined. Two different methods of collecting data at junctions are described and compared, and the advantages of a system which incorporates both video techniques and a microprocessor-based system developed at RHC are detailed. Empirical results on the relationships between gap acceptance parameters and various factors are presented: the effects of major road speeds and flow, manoeuvre time of turning vehicles, class of vehicle in each traffic stream, gender of driver and presence of passengers are investigated. Two models of gap acceptance by queues of vehicles are then discussed. Preliminary results from a large scale study to test the validity of a conflict simulation model developed at RHC are reported, which indicate that the model may be used to compare accident risk in different situations. Some examples of the ways in which safety at junctions varies with particular parameters are given, using results from the model. Details of the computer programs used to analyse gap acceptance data from T-junctions are appended.

<p> Flooding is recognized as a catastrophic event and a threat to the load carrying capacity of pavements around the world. In the aftermath of flooding, the pavement structure could be inundated and fully saturated. The significant increase of water within pavement layers may cause weakness and induce damage with traffic loading, subsequently increasing maintenance costs and shortening pavement service life. </p><p> The assessment of the structural performance and capacity of flooded pavements remains complicated due to lack of structural data immediately following flooding, and information about the pavement structure and materials is not always readily available. Currently, the decision to open roads for traffic is based on the assessment of the pavements, which relies on visual inspection and experience. An incorrect assessment of the flooded pavement structural capacity due to unforeseen conditions may lead to unexpected outcomes or failure. The objective of this dissertation is to advance the current knowledge of the behavior of flooded pavements, based on their performance properties and structural capacities. </p><p> Several methodologies have been developed and examined for a set of pavement structures with different material types using layered elastic analysis to (1) investigate the pavement response to traffic loads under different moisture conditions, (2) identify the important parameters that affect the performance of inundated pavements, (3) investigate the influence depth of the subsurface water level at which the road can withstand traffic with zero to minimum deterioration, (4) estimate the in-situ pavement surface deflection, and (5) identify the catastrophic failure of pavements in post-flood events. </p><p> The findings showed a significant reduction in structural capacity when the pavement structure was in the fully saturated condition, but the road could regain its capacity after desaturation and recession of water level. The influence depth for the subsurface water level was found to be dependent on pavement structure and material type. The most accurate method to estimate the in-situ measured deflection is to divide the soil layer into several layers in the layered elastic analysis. Accurate layer thicknesses, traffic type, and interlayer bond condition are the important factors for evaluating changes in expected horizontal strain at the bottom of asphalt layer, used for predicting fatigue cracking pavement performance. The type of base and subgrade materials are the most important factors for evaluating the changes in expected vertical strain at the top of subgrade layer, used to predict pavement rutting performance. This dissertation provides information to agencies that will enhance their understanding of the performance and structural capacity of pavements in post-flood events.</p>

M.Ing. (Transportation) / Please refer to full text to view abstract

The proportion of individuals aged 65 and over is growing at an astronomical rate in the United States, and some estimate that this demographic age group will double by the year 2025. Aging adults are primarily dependent on the personal automobile as their main source of transportation. Older adults and adults nearing retirement age also tend to reside in suburban neighborhoods and rely heavily on personal vehicles. Since most of the United States is characterized by automobile dependent suburbanization, where the majority of development is suburban low-density sprawl, this may become problematic for aging populations who may be uncomfortable driving longer distances and making more trips. These trends invite the question of whether the deck is stacked against individuals approaching retirement age (50-64) and aging populations (65 and up). This study examines aging populations’ mobility and determines whether they have different travel patterns than their younger cohorts. Additionally, this investigation explores whether or not travel patterns across age groups result in differential access to particular goods and services, as well as differences in travel environment characteristics in a metropolitan area. This research proposes an approach based on Time Geographic Density Estimation (TGDE) to identify activity spaces across different age cohorts in order to identify differences in the mobility and travel behavior of aging adults. TGDE is an established technique in the literature, which blends the notion of activity spaces with the computation of probabilistic potential path trees along a transportation system. In this way it establishes an ‘extent’ or overall mapping of the activity space of an individual, but is able to further refine that extent to identify the most likely places they are able to visit within that geography. Data on origin and destination trips and travel times are taken from the National Household Travel Survey (NHTS) Florida add-on for the study area of Orlando Metropolitan Statistical Area (MSA). Transportation is an important consideration in planning for aging populations, and analyzing differences in how older adults travel compared to their younger counterparts can offer insight into the diverse needs of this group. / A Dissertation submitted to the Department of Geography in partial fulfillment of the requirements for the degree of Doctor of Philosophy. / Summer Semester 2017. / April 28, 2017. / Accessibility, Aging Populations, Transportation / Includes bibliographical references. / Mark Horner, Professor Directing Dissertation; Jeffrey Brown, University Representative; Christopher Uejio, Committee Member; David Folch, Committee Member.

Recently, in the United States, roundabouts have been used to replace signalized and unsignalized intersections because the use of roundabouts has safely reduced crash severity and fatality at intersections by eliminating or altering conflict types and forcing drivers to reduce their speed as they drive in and through it. Generally, in Florida, due to the recent introduction of roundabouts and the complexity of some roundabouts (especially multi-lane roundabouts), drivers are most times not familiar with this type of intersection and therefore involve in a crash. Therefore, it is necessary to evaluate the safety effects of roundabout amongst drivers and especially aging drivers since it is projected by the United States Census Bureau, that the population of persons aged 65 and above in Florida is expected to be more than 26% of the total population by the year 2025 and by the year 2030 all the baby boomers will be older than age 65. Thus, the objectives of this study were to evaluate the effectiveness of roundabouts among drivers by comparing the crash severity of roundabout crashes involving aging drivers versus their young and middle-aged counterparts and to determine the relationship between the crash frequency, the geometric characteristics of roundabouts and the signage of roundabouts .In order to achieve these objectives, the type and severity of roundabout crashes, as distributed according to participant age will be investigated Binomial logistic regression model was used to evaluate injury severity differences in roundabout crashes amongst drivers of different age groups while evaluating the differences in factors relating to roundabout crashes which includes the time of the day, day of the week, the type of roundabout, weather conditions, lighting conditions, the geometric design of the roundabout, vehicle speed and the crash's at-fault driver age. Also, the negative binomial regression model was used to determine the relationship between the total number of crashes, the roundabout speed, the geometric conditions and signage of the roundabouts selected for the count study. The results from this study indicate that vehicle speed and average annual daily traffic are the most important factors affecting the severity of crashes among all age groups at roundabouts and that the total number of crashes on roundabouts are affected by the traffic volume, the number of circulatory roadway lanes, the number of legs, the roundabout speed, inscribed circle. diameter, and the presence of signages and signals such as chevron, pedestrian sign, approach marking, lane use control symbol marking and pavement word. For aging drivers, the number of vehicles involved in the crash, the vehicle speed of the at-fault driver and the type of crash are significant at 95% confidence interval in affecting their crash severity while the annual average daily traffic is the only significant factor at 95% confidence interval affecting the frequency of aging driver crashes at roundabout This study focuses on developing recommendations for roundabout implementation, improved design guidelines and additional recommendations for improved for improved safety of drivers in the State of Florida. / A Thesis submitted to the Department of Civil and Environmental in partial fulfillment of the requirements for the degree of Master of Science. / Fall Semester 2018. / November 26, 2018. / Includes bibliographical references. / Lisa K. Spainhour, Professor Directing Thesis; Eren E. Ozguven, Committee Member; Maxim Dulebenets, Committee Member.

Evacuating individuals and allocating space in shelters are complex tasks that depend on disaster characteristics, roadway network characteristics, the demographics and socioeconomic status of people in the affected region, as well as the effectiveness of the emergency plans. This problem becomes even more challenging when special needs (access and functional needs) populations and those with pets are considered since they may require more time in the event of an evacuation along with more space in shelters. Satisfying the needs of aging victims during emergency evacuations is critical and requires extra attention in the presence of highly uncertain disaster conditions. During Irma, it was very hard to manage the evacuation of aging people who had disabilities and mobility restrictions, did have special needs or pets. This study develops a Geographical Information Systems (GIS)-based methodology to measure and assess the transportation accessibility of these critical facilities through a diverse set of case study applications in the State of Florida. This research presents a timely evaluation and assessment of aging-focused evacuations towards providing better decision support during emergency transportation operations. This analysis is applied on a case study application set in Florida with a focus on the delays, evacuation travel times and critical bottlenecks, which can be vital for aging victims’ safety and survival. This study also emphasizes the use of GIS-based maps and modeling scenarios in support of emergency evacuation operations, in order to both satisfy the needs of aging people and account for real-world disruptions such as road closures. Additionally, a variety of scenarios are constructed to simulate evacuating 65+ and 85+ populations living in the evacuation zone, providing dynamic congested travel times. Finally, a capacitated p-median optimization model is implemented to maximize the accessibility and capacity of the existing shelters for 85+ populations with special needs (access and functional needs) or pets. Results indicate that the location and allocations of people to shelters are sensitive to demographics and roadway conditions, and the accessibility to shelters can be improved for this group of people based on optimization model results. A contribution of the research will be the evaluation of emergency evacuation performance of the transportation network under multiple disaster scenarios and the detailed modeling of key transportation facilities where special needs would take place. By exploring the use of multi-layered approach for emergency operations, this research will also increase the performance in evacuating aging people who has limitations. / A Dissertation submitted to the Department of Civil and Environmental Engineering in partial fulfillment of the requirements for the degree of Doctor of Philosophy. / Fall Semester 2017. / November 7, 2017. / Includes bibliographical references. / Eren Erman Ozguven, Professor Directing Dissertation; Jeff Brown, University Representative; Ren Moses, Committee Member; John O. Sobanjo, Committee Member.