The growing concern for the shortage of primary care physicians (PCPs) prompted a government legislation to designate areas where shortage in the delivery of primary care services occurs. The implemented systems (e.g., HPSA, MUA, and MUP) analyze utilization of health services within confined administrative units and fail to account for spatial interactions that occur across administrative borders. This research examines the spatial accessibility to PCPs and the underlying demographic and socioeconomic settings. With the Nashville Metropolitan Statistical Area (MSA) as a study area, this study utilized data from the U.S. Census 2000 and 2010, as well as the known locations of (PCPs) collected in 2010. Geographic Information Systems (GIS) provided the tools by which the processing and analysis of the data was carried out. Specifically, network analysis was applied to estimate travel time and service area coverage. A Two-Step Floating Catchment Area (2SFCA) method was implemented to measure spatial accessibility to PCPs. This method was applied to measure accessibility at the level (census block) that most accurately represents the spatial population of the Nashville MSA. In addition, this research implemented several distance-decay functions in addition to the dichotomous function of the standard 2SFCA method. This research has found that the majority of the population residing in the Nashville MSA enjoyed good spatial accessibility to PCPs. However, the highest percentages of those resided in areas of low accessibility were located in periphery rural areas as well as isolated areas poorly connected to the roadway network due to certain physical barriers such as lakes and streams. Moreover, this research has found that, in general, non-spatial factors intensified the most where there was good accessibility to PCPs.

The idea behind this report is based on the fact that it is not only the number of users in the traffic network that is increasing, the number of connected devices such as probe vehicles and mobile sources has increased dramatically in the last decade. These connected devices provide large-scale mobility data and new opportunities to analyze the current traffic situation as they traverse through the network and continuously send out different types of information like Global Positioning System (GPS) data and Mobile Network Data (MND). Travel demand is often described in terms of an Origin Destination (OD) matrix which represents the number of trips from an origin zone to a destination zone in a geographic area. The aim of this master thesis is to develop and evaluate a data-driven method for estimation of dynamic OD matrices using unsupervised learning, sensor fusion and large-scale mobility data. Traditionally, OD matrices are estimated based on travel surveys and link counts. The problem is that these sources of information do not provide the quality required for online control of the traffic network. A method consisting of an offline process and an online process has therefore been developed. The offline process utilizes historical large-scale mobility data to improve an inaccurate prior OD matrix. The online process utilizes the results and tuning parameters from the offline estimation in combination with real-time observations to describe the current traffic situation. A simulation study on a toy network with synthetic data was used to evaluate the data-driven estimation method. Observations based on GPS data, MND and link counts were simulated via a traffic simulation tool. The results showed that the sensor fusion algorithms Kalman filter and Kalman filter smoothing can be used when estimating dynamic OD matrices. The results also showed that the quality of the data sources used for the estimation is of high importance. Aggregating large-scale mobility data as GPS data and MND by using the unsupervised learning method Principal Component Analysis (PCA) improves the quality of the large-scale mobility data and so the estimation results. / <p>Examensarbetet är utfört vid Institutionen för teknik och naturvetenskap (ITN) vid Tekniska fakulteten, Linköpings universitet</p>