PATH

Developing Calibration Tools for Microscopic Traffic Simulation Final Report Part III: Global Calibration - O-D Estimation, Traffic Signal Enhancements and a Case Study

Zhang, Michael
Ma, Jingtao
Singh, Shailendra P.
Chu, Lianyu
2008

The central goal of this research is to develop a systematic framework and the support tools to ease, streamline and speed up the calibration of micro simulation projects. Part III of the final report documents the accomplishments achieved in the second phase of the research project. They include the following.First, to overcome the lengthy time it takes for GA to obtain local and global driving behavior modeling parameters, we implemented a faster heuristic optimization technique, the simultaneous perturbation stochastic approximation (SPSA) and compared its performance with other...

Fault Detection And Tolerant Control For Lateral Guidance Of Vehicles In Automated Highways

Patwardhan, Satyajit Neelkanth
1994

In this dissertation, the problem of fault tolerant control of automobiles is addressed. The three main problems handled in the dissertation are tire burst, sensor fault detection and slip angle control. The tire burst and sensor faults are important failure modes for automated highways, whereas the slip angle control problem is important during severe maneuvers for enhancing the vehicle safety.

Literature Review Report on Benefit/Cost Studies and Evaluations of Transit Management Systems

Jia, Xudong
Sullivan, Edward
Nuworsoo, Cornelius
Hockaday, Neil
2008

This study addresses the benefits and costs of Advanced Public Transportation Systems (APTS) applications in small and medium sized transit agencies using the research test implementation of a small transit oriented Intelligent Transportation System (ITS) on San Luis Obispo Transit as a case study. The Smart Transit System at San Luis Obispo is in a pre-commercialized state and implements the Efficient Development of Advanced Public Transportation Systems (EDAPTS) framework concept (Gerfen, 2001). The system has many potential benefits that will be identified and evaluated from a cost of...

New Approach to Bottleneck Capacity Analysis: Second Interim Report, Work Accomplished During Fiscal Year 2004-2005

Banks, James
2006

This report documents work accomplished during Fiscal Year 2005-2005 as a part of a research project entitled “New Approach to Bottleneck Capacity.” This project is developing an alternative to the traditional Highway Capacity Manual approach to capacity analysis in which capacity flow [either pre-queue flow (PQF) or queue discharge flow (QDF)] is related to a set of intervening variables, including the average time gaps in the critical lane (i. e., that with the highest flow rate) and the distribution of flow across the lanes, represented by the critical lane flow ratio (i. e., the flow...

Regulation Layer Software Integration

Deshpande, Akash R.
1999

The project reuses the sensor and actuator interface software developed by California PATH for the DEN1097 automated highway system demonstration on Highway I17 in San Diego during August 1997. This software is provided on the QNX operating system. It interfaces with the magnetometers, radars, and the various intenal sensors such as wheel speed, engine speed, steering angle, etc, as well as with the actuators such as throttle, brake, and steering. In this project, we wrote an interface process that communicates between the driver process described above and the controller process described...

San Francisco Bay Area US-101 Existing Conditions, ITS Assets, and Active Transportation and Demand Management Assessment

McKeever, Benjamin
Skabardonis, Alexander
Mauch, Michael
Campbell, Robert
Alexiadis, Vassili
Wornum, Christopher
2018

The 58.5-mile long Highway 101 corridor from the Bay Bridge to the SR 85/US-101 interchange in South San Jose accommodates just over 2.6 million trips on an average weekday. Travel delays on the US-101 corridor over the 2012-2016 five-year period increased by more than 91% (an average delay increase of over 18% per year). Given that California’s economy recently grew to become the sixth largest in the world, this waste of time stuck in traffic ranks among the most consequential economic inefficiencies in the world; workers in this region produce about 15 percent of California’s annual...

Collision Avoidance Analysis for Lane Changing and Merging

Jula, Hossein
Kosmatopoulos, Elias B.
Ioannou, Petros A.
1999

One of the riskiest maneuvers that a driver has to perform in a conventional highway system is tomerge into the traffic and/or to perform a lane changing maneuver. Lane changing/mergingcollisions are responsible for one-tenth of all crash-caused traffic delays often resulting incongestion. Traffic delays and congestion, in general, increases travel time and has a negativeeconomic impact.In this paper, we analyze the kinematics of the vehicles involved in a lane changing/mergingmaneuver, and study the conditions under which lane changing/merging crashes can be avoided.That is, given a...

ITS Information And Services To Enhance The Mobility Of Disabled Travelers

Chen, Wan-hui
Uwaine, Rochelle
Klaver, Kelley
Kurani, Ken
Jovanis, Paul P.
1998

This study examined the potential of advanced information systems to increase the mobility of disabled travelers using public transportation. A stated preference survey inquired as to whether subjects would make more trips by transit, paratransit, and/or real-time paratransit if kiosk, on-board, in-home, and/or personal information systems were available. The results show that these systems do have the potential to increase the use of public transportation by disabled travelers, as they allow for more trip flexibility that what is currently available. Regression and log-linear models show...

Potential Erroneous Degradation of High Occupancy Vehicle (HOV) Facilities

Fournier, Nicholas, PhD
Farid, Yashar Zeinali, PhD
Patire, Anthony David, PhD
2021

This document is the final report for Task ID 3710 (65A0759), a project titled “Potential Erroneous Degradation of High Occupancy Vehicle (HOV) Facilities”. This report contains a compilation of three previous technical memorandums titled “Survey of Data-Mining Methods”, “Performance of Methods”, and “Magnitude of HOV Degradation”. HOV lane sensors in Caltrans’ Performance Management System (PeMS), are sometimes misconfigured as general-purpose lanes. In this situation, HOV lane data is mistakenly aggregated with general-purpose lane data and vice versa. The purpose of this project was to...

Quantifying the Performance of Countermeasures for Collision Concentration Related to Ramp/Freeway Mainline Junctions

Lee, Joon ho, PhD
Chan, Ching-Yao, PhD
Ragland, David R., PhD
2009

This study performed before-and-after analyses (comparisons of collisions before and after the construction of auxiliary lanes) on collision rate at nine study sites in California in order to achieve two objectives: (i) to estimate the freeway Crash/Collision Reduction Factor (CRF) for auxiliary lanes, and (ii) to develop design guidelines for the construction of auxiliary lanes. Findings indicate that on average, collision rates decreased by 17.3 percent at nine study sites. The study also found that after construction of auxiliary lanes at two study sites, collision rates increased when...