Roads/Highways

Effectiveness of Adaptive Traffic Control for Arterial Signal Management

Gomes, Gabriel
Skabardonis, Alexander
2009

A number of adaptive control algorithms have been developed in the US and overseas. However, the practical implementation of adaptive control is limited especially in California. There is a need to develop adaptive control algorithms, evaluate their performance through a field test, and develop a deployment plan for possible Statewide application. The objectives of the study are identify and select the most promising of existing adaptive control algorithms, develop improved algorithm(s) as appropriate, conduct field tests on real-world arterials, and develop recommendations for deployment...

Integrated Roadway / Adaptive Cruise Control System: Safety, Performance, Environmental and Near Term Deployment Considerations

Zhang, Jianlong
Ioannou, Petros
2004

In this project, we design two new Adaptive Cruise Control (ACC) systems based on driver comfort, safety, vehicle following performance, environmental and traffic flow characteristics considerations. A new variable time headway rule is proposed and used to meet these considerations. Analysis and simulations are used to evaluate and compare the two designs. The first ACC system (referred to as ACC01) incorporates two controllers: one for speed tracking and one for vehicle following. The second ACC system (referred to as ACC02) treats the vehicle following task as a special speed tracking...

Light Rail System Safety Improvements Using ITS Technologies

Chira-chavala, Ted
Coifman, Ben
Empey, Dan
Hansen, Mark
Lechner, Ed
Porter, Chris
1997

This report describes research which studied identifying and analyzing the effectiveness of countermeasures designed to reduce light rail crashes. Focus is in collisions with road vehicles at intersections. The light rail system for the Santa Clara County Transportation Agency in California served as the focus of the study.

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...

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...

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...

System Fault Detection in Human-Augmented Automated Driving

Cohn, Theodore
2001

Lateral control of a vehicle in the Automated Highway System (AHS) has been formulated and simulated as part of the hierarchical AHS control structure. In that structure, lateral control resides in the vehicle, and is implemented as a closed-loop control system with the lateral deviation of the vehicle from a reference position as a controlled variable and the steering angle or its rate as a controlling input. The PATH AHS scenario has assumed a road reference and sensing system based on magnetic markers equally spaced along a highway lane. Freedom in the selection of the polarity of each...

Lateral Control of Heavy Vehicles for Automated Systems

Hingwe, Pushkar
Wang, Jen-Yu
Tai, Meihua
Tomizuka, Masayoshi
2003

This is the final report for MOU 313, "Lateral Control of Heavy Vehicles for Automated Highway Systems". It address the following task items: Analysis and synthesis of control algorithms based on system identification and calibration results (Task 4. in the MPU), Closed loop results at highway speeds (Task 5), limits and persormance of sensors, actuators and control schemes as infered from data collected during closed loop experiments at 55 MPH (task 6) and baseline safety requirements based on closed loop data (task 7) Five controllers were designed based on the model identification study...