Crash Risk Reduction at Signalized Intersections Using Longitudinal Data

This study extends the previous work of Burkey and Obeng (2004) that examined the impact of red light cameras on the type and severity of crashes at signalized intersections in Greensboro, NC. The extension takes the following form. First, we extend the data to cover 57 months, and to include demographics, technology variables, the condition of a driver at the time of the crash, vehicle characteristics, land use and visual obstruction. Second, instead of examining the impact of red light cameras, we focus on identifying the determinants of crash severity, two-vehicle crashes, and property damage costs. The major findings are that the safety impacts of seatbelt use outweigh the impacts of airbags deploying because the latter tends to increase evident injuries and property damage costs, while the former reduces these injuries. We also find that head-on collisions and under rides increase evident injuries. For two-vehicle crashes, we find that the risk of severe injuries increases in pickup-pickup crashes and SUV-pickup crashes, while the risk of possible injuries increases in car-truck crashes. For property damage costs, we found the condition of the driver at the time of the crash (i.e., illness, impaired, medical condition, driver falling asleep, driver apparently normal) to be important determinants in increasing these costs. The types of accidents that we found to increase property damage costs are running into a fixed object and under rides. Finally, we found that property damage costs of crashes are low where the land uses are commercial and institutional suggesting that the accidents that occur in these areas are minor.longitudinal data; accidents; intersections

Examining the Inefficiency of Transit Systems Using Latent Class Stochastic Frontier Models

This paper estimates a single class stochastic cost frontier model that accounts for heterogeneity by including background variables and a latent class model of the same specification. It is found that both the two-sided random errors and one-sided errors (cost inefficiency) are substantially smaller in the latter model than it is in the former, suggesting possible bias in the estimates of inefficiency from the single class model. Further, 58.9%–68.39% of the calculated inefficiencies are due to differences in technology captured by the latent classes. The paper concludes that using background variables only to capture heterogeneity may exaggerate measured inefficiencies in transit systems and suggests the latent class approach as a solution

Crash Risk Reduction at Signalized Intersections Using Longitudinal Data

This study extends the previous work of Burkey and Obeng (2004) that examined the impact of red light cameras on the type and severity of crashes at signalized intersections in Greensboro, NC. The extension takes the following form. First, we extend the data to cover 57 months, and to include demographics, technology variables, the condition of a driver at the time of the crash, vehicle characteristics, land use and visual obstruction. Second, instead of examining the impact of red light cameras, we focus on identifying the determinants of crash severity, two-vehicle crashes, and property damage costs. The major findings are that the safety impacts of seatbelt use outweigh the impacts of airbags deploying because the latter tends to increase evident injuries and property damage costs, while the former reduces these injuries. We also find that head-on collisions and under rides increase evident injuries. For two-vehicle crashes, we find that the risk of severe injuries increases in pickup-pickup crashes and SUV-pickup crashes, while the risk of possible injuries increases in car-truck crashes. For property damage costs, we found the condition of the driver at the time of the crash (i.e., illness, impaired, medical condition, driver falling asleep, driver apparently normal) to be important determinants in increasing these costs. The types of accidents that we found to increase property damage costs are running into a fixed object and under rides. Finally, we found that property damage costs of crashes are low where the land uses are commercial and institutional suggesting that the accidents that occur in these areas are minor

Running the Gamut: Music, the Aesthetic, and Wittgenstein's Ladder

Ludwig Wittgenstein’s thinking about musical aesthetics (a small but persistent strain in his writings) focused primarily on questions of demonstration and proper performance: how should this waltz or march sound? These emphases were part of a modernist-inspired effort to move aesthetics down from the heights of Kantian contemplation onto the plain of quotidian practice. But Wittgenstein does not so much escape Kant’s formulations as he extends them. The result opens the possibility of elaborating ordinary, even banal, comments about music into complex accounts of musical meaning

The Effects of Subsidies on Public Transit Long-Run Costs

This paper investigates sources of public transit long-run cost increases attributable to transit subsidies. The sources include wage, vehicle capital price and service increases. Service expansion is found to be the major source. Transit cost increases related to subsidies are classified as input price, output and finance effects of these subsidies. Transit costs are more responsive to federal operating subsidies, followed in declining order by local operating, state operating and capital subsidies, respectively

A detailed investigation of crash risk reduction resulting from red light cameras in small urban areas

This is an update to the October, 2003 version of this report. Using the latest available data, we include an additional 12 months of accident data. Additionally, several data coding errors were discovered in the original data set, and corrected for this report. Therefore, results from the October, 2003 report should be disregarded. This paper analyzes the impact of red-light cameras (RLCs) on crashes at signalized intersections. It examines total crashes and also breaks crashes into categories based on both severity (e.g. causing severe injuries or only property damage) and by type (e.g. angle, rear end). Prompted by criticism of the simplistic methods and small data sets used in many studies of red light cameras, we relate the occurrence of these crashes to the characteristics of signalized intersections, presence or absence of RLC, traffic, weather and other variables. Using a large data set including 26 months before the introduction of RLCs, we analyze reported accidents occurring near 303 intersections over a 57 month period, for a total of 17,271 observations