Title: WEATHER IMPACT ON ROAD ACCIDENT SEVERITY IN MARYLAND YUE LIU, M.S. in Civil and Environmental Engineering, 2013 Directed By: Professor and Chair Ali Haghani, Department of Civil and Environmental Engineering This study was conducted to analyze and quantify the impact of weather factors on road accident severity, based on Maryland accident data during 2007-2010. In order to find a better ...

Abstract. This paper explains why computing the marginal effect of a change in two variables is more complicated in nonlinear models than in linear models. The command inteff computes the correct marginal effect of a change in two interacted variables for a logit or probit model, as well as the correct standard errors. The inteff command graphs the interaction effect and saves the results to al...

This paper estimates a locational choice model to assess the demand for local public services, using a data set where individuals chooses between 26 municipalities within a local labor market. We assess the importance of the IIA assumption by comparing the predictions of three difference models; the conditional logit (CL) model, the mixed logit (MXL) model, and the multinomial probit (MNP) mode...

Abstract-A discrete choice model is presented that explicitly recognizes differences in the error structure associated with a single “oddball” alternative within the choice set that has properties not common to the other alternatives. The model purportedly resolves questions related to the use of alternative-specific variables in transportation choice models to capture the effects of attributes...

While there is growing application of generalized ordered outcome model variants (widely known as Generalized Ordered Logit (GOL) model and Partial Proportional Odds Logit (PPO) model) in crash injury severity analysis, there are several aspects of these approaches that are not well documented in extant safety literature. The current research note presents the relationship between these two var...

In many high-stakes testing programs, testlets are used to increase efficiency. Since responses to items belonging to the same testlet not only depend on the latent ability but also on correct reading, understanding, and interpretation of the stimulus, the assumption of local independence does not hold. Testlet response theory (TRT) models have been developed to deal with this dependency. For b...

In 2008, financial tsunami started to impair the economic development of many countries, including Taiwan. The prediction of financial crisis turns to be much more important and doubtlessly holds public attention when the world economy goes to depression. This study examined the predictive ability of the four most commonly used financial distress prediction models and thus constructed reliable ...

In this paper we investigate the value of travel time savings. Estimation of this is in most cases based on samples using a specific mode. We use a mixed logit model to estimate the VTTS together with an auxiliary probit equation to capture the fact that the sample is non random. The results show that the probit equation in some cases gives extra information that can be used to improve the VTTS...