Sustainability and livability as concepts that indicate the capability of transportation systems to maintain social well-being have been widely accepted as critical principles to improve the quality of life and health in communities. This study introduced a geographic information system as the basis for a performance measurement system to assess the two goals from the standpoint of transportation systems. The city of Buffalo, New York, was used as the case study. Various data were collected, and 20 sustainability and livability related performance measures (PMs), including transportation attributes, land use measures, living condition indicators, and systemwide indexes, were developed. Analysis of the PMs raised several policy implications and led to some suggestions. Lessons and challenges from the PM development process are summarized to help other relevant initiatives. The PMs, the supporting database, the case study, and the findings produced by the research are expected to help a wide range of stakeholders, including policy makers, planners, and transportation engineers, to gain more insights into transportation-oriented sustainability and livability performance measurement.

The decisions of vehicular mode choice by businesses and commercial sectors in urban areas are addressed with attention to the unique trip-chaining behavior of commercial vehicles. Travel diary data from a collection of large-scale commercial vehicles in the Denver, Colorado, metropolitan area were used for analysis. Four types of travel activities were surveyed: business meetings, pickup and drop-off of people, pickup and delivery of cargo, and service calls. The survey results indicated that automobiles, pickup trucks, sport utility vehicles, single-unit trucks, and combination trucks were the main vehicular modes for travel with commercial purposes. The original survey data were sorted into trip-based and tour-based data sets for measuring commercial vehicle travel activities. A “trip” is defined as travel from one stop to another, and a “tour” is an entire travel journey starting from and ending at the home base of a vehicle with visits to various locations of interest. Discrete choice modeling techniques, particularly multinomial logit and nested logit models, were used to quantify the relationship between decisions on the choice of commercial vehicular mode and their affecting factors, and the two data sets were used separately. The modeling results indicate that mode choice by the commercial sector is travel specific, territory dependent, and cargo sensitive and varies by company. As proved by the comparison of trip-based and tour-based models, the tour is an intuitively and quantitatively better unit for measuring the travel activities of commercial vehicles and for modeling behavior of mode choice of the commercial sectors.

BackgroundThe aim of this study was to explore the influence of different input arteries on the parameters of computed tomography (CT) perfusion imaging for patients with different degree of stenosis of internal carotid artery (ICA).Material/MethodsForty patients were enrolled in the present study and divided into mild, moderate, severe stenosis and occlusion groups respectively with each 10 patients in each group. In reconstruction of cerebral CT perfusion (CTP) images, each raw perfusion image was reconstructed 3 times based on different reference input artery, including bilateral middle cerebral artery (MCA) and basilar arteries (BA). Region of interest (ROI) was drawn in the central territories of bilateral anterior cerebral artery, middle cerebral artery and posterior cerebral artery. And regional cerebral blood flow (rCBF) regional cerebral blood volume (rCBV), mean transit time (MTT), time to peak (TTP) and delay time (DT) were obtained from those ROI corresponding perfusion images.ResultsIn patients with mild and moderate ICA stenosis, there was no significant difference of perfusion parameters based on different input arteries (P>0.05). However, in severe ICA stenosis and occlusion CBF, MTT, and DT were significant different in affect side of the MCA group compared to the others (P<0.05).ConclusionsLarge intracranial artery can be selected as the input artery for patients with mild to moderate ICA stenosis, while for patients with severe stenosis and occlusion of ICA, the contra lateral middle cerebral artery or basilar artery would be better choice.

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