Practical recommendations are given that researchers, traffic police, medical authorities, nongovernmental organizations (NGOs), educational institutions, and municipalities can adopt to lower the risk of pedestrian crashes.

No abstract

This article investigates the factors affecting drivers' stated behavior in adverse visibility conditions and examines whether drivers rely on and follow advisory or warning messages displayed on portable changeable message signs (CMS) and/or variable speed limit (VSL) signs in different visibility and traffic conditions, and on two types of roadways: freeways and two-lane roads. A multiple-approach survey was designed to collect opinions and stated data from Central Florida drivers.Categorical data analysis techniques such as conditional distribution, odds ratio, and chi-squared tests were applied. In addition, two modeling approaches, bivariate and multivariate probit models, were estimated. The results revealed that gender, age, road type, visibility condition, and familiarity with VSL sign were the significant factors affecting the stated likelihood of reducing speed following CMS/VSL instructions in reduced visibility conditions. Other objectives of this study were to determine the content of messages that would achieve the best perceived safety and drivers' compliance and to examine the best way to improve safety during these adverse visibility conditions. The results indicated that respondents thought that "Caution-fog ahead-reduce speed" was the best message and that using that CMS and VSL signs together was the best way to improve safety during such inclement weather situations. Based on the findings of the present study, several recommendations are suggested as guidelines to improve safety in reduced visibility conditions.

Frequent pedestrian casualties in crowded facilities have brought increasing attention to the study of pedestrian dynamics in such facilities. In this paper, a microsimulation assignment model for multidirectional pedestrian movement in crowds is presented. The model attempts to overcome many limitations of existing models by incorporating various pedestrian behavior rules under a particular set of situations. It also adopts a cellular automata discrete system that allows detailed representation of pedestrians’ walkways and movement areas. The model is applied to the “mataf” system, which is located at the main prayer hall of the holy noble mosque known as Al-Haram Al-Shareef Mosque in Mecca, Saudi Arabia. A set of simulation experiments is designed to illustrate use of the model to study the performance of the mataf system by consideration of different operational conditions as well as different pilgrim behavior rules.

The approach used in practice to predict short-run transport equilibria involves a sequential process, often with four stages: trip generation, trip distribution, modal split, and traffic assignment. This approach has an inherent weakness—its prediction need not be internally consistent. This deficiency has motivated attempts to predict all four stages simultaneously. The (conventional) sequential and simultaneous models are compared by calibrating and applying both models to the urban transportation network of Riyadh, Saudi Arabia. The main finding is that the simultaneous model produces better traffic flow predictions than the prediction of the conventional sequential model. These predictions are much better for the heavy volume links that are the most important links in the prediction process.

No abstract

No abstract

No abstract