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This paper describes the findings from the application of the INTRAS microscopic simulation model to evaluate the traffic performance at major freeway weaving sections. The work performed is part of an ongoing research project to develop improved weaving analysis procedures that are particularly applicable to California conditions. The INTRAS model was modified to predict the speeds of weaving and nonweaving vehicles and applied on eight major freeway weaving sections for a range of traffic conditions at each site. Good agreement was obtained between the measured and predicted values....

We present a system that displays travel time predictions in real time on changeable message signs (CMS) in California. Using loop detector data, this system calculates predicted travel times on designated routes every five minutes. An automated process displays the current travel time predictions on the appropriate CMS’s. We demonstrate the benefits of real time travel time prediction. Historical analysis show that route decision based on CMS almost always identifies the quickest route when alternates are available. Regardless of whether alternate routes exist, prediction reduces travel time...

An advanced machine vision system is presented that automatically extracts vehicle trajectories over long freeway sections from video data. For each vehicle, its dimension and initial position are robustly given by the vehicle detection algorithm, and a separate tracking algorithm is used to extract the vehicle’s trajectory from the images of multiple cameras. The algorithms overcome the limitations of machine vision algorithms previously proposed that have difficulty to robustly obtain accurate vehicle positions in the presence of shadows and occlusions. Using the system, we generated a...

Traditionally, the amount of air pollutant emissions from motor vehicles—hydrocarbons, carbon monoxide, and oxides of nitrogen—is estimated from emission factors based on trip and vehicle miles traveled and aggregate measures of vehicle activity (e.g., average vehicle speed). This method is not reliable for urban networks, as it does not consider the effect of traffic signals and congestion. There is a need to predict vehicle activity by mode of operation, i.e., time spent in cruise, acceleration, deceleration, and idle to obtain improved emission estimates. An analytical model for...