Data

In Traffic Flow, Cellular Automata = Kinematic Waves

Daganzo, Carlos F.
2004

This paper proves that the vehicle trajectories predicted by (i) a simple linear carfollowing model, CF(L), (ii) the kinematic wave model with a triangular fundamental diagram, KW(T), and (iii) two cellular automata models CA(L) and CA(M) match everywhere to within a tolerance comparable with a single "jam spacing". Thus, CF(L) = KW(T) = CA(L,M).

California’s Freeway Service Patrol Program: Management Information System Annual Report Fiscal Year 2020-21

Mauch, Michael
Skabardonis, Alex
2022

The Freeway Service Patrol (FSP) is an incident management program implemented by Caltrans, the California Highway Patrol and local partner agencies to quickly detect and assist disabled vehicles and reduce non-recurring congestion along the freeway during peak commute hours. The first FSP program was piloted in Los Angeles and was later expanded to other regions by state legislation in 1991. As of June 2020, there were sixteen participating FSP Programs operating in California, deploying 305 tow trucks and covering over 1,900 (centerline) miles of congested California freeways. The...

Evaluation of Coordinated Ramp Metering (CRM) Systems in California

Mauch, Michael
Skabardonis, Alexander
2021

Freeway on-ramp metering (RM) has been extensively used as a traffic control strategy to regulate the entry of the on-ramp vehicles to prevent congestion at the freeway merging areas and preserve the freeway capacity. Benefits of RM include improved freeway travel times, improved travel time reliability, and accident reductions. Fixed-rate ramp metering strategies are based on historical data and implemented by time of day. Traffic responsive RM strategies are based on real time freeway traffic data provided by loop detectors at the vicinity of the on-ramp. Coordinated RM determine the...

The Development of An Accident Database to Structure Land Use Regulations in Airport Runway Approach Zones

Cooper, Douglas L.
Gillen, David
1993

This report presents and describes 400 aviation accidents which occurred within five miles of an airport. Section 2 contains a description of the development of the database and a discussion of the criteria used in selecting accidents for the database. Section 3 provides a description of the database itself as well as a set of statistics that provide a comprehensive overview of the accidents. A set of aircraft accident contours developed from the accident data points is presented in section 4. The purpose of these contours is to provide a picture of the distribution of accidents over space...

Benchmarking “Smart City” Technology Adoption in California: Developing and Piloting a Data Collection Approach

Frick, Karen Trappenburg, PhD
Kumar, Tanu, PhD
Mendonça Abreu, Giselle Kristina
Post, Alison, PhD
2021

In recent years, “smart city” technologies have emerged that allow cities, counties, and other agencies to manage their infrastructure assets more effectively, make their services more accessible to the public, and allow citizens to interface with new web- and mobile-based operators of alternative service providers. This project reviews the academic literature and other sources on potential strengths, weaknesses, and risks associated with smart city technologies. No dataset was found that measures the adoption of such technologies by government agencies. To address this gap, a methodology...

Critique of a Freeway On-Ramp Metering Scheme and Broader Related Issues

Cassidy, Michael J.
2002

Offered here is a critique of a simple scheme recently proposed for metering freeway on-ramps. An earlier report of this scheme's potential for reducing commuter delay is shown to be exaggerated. The discussion makes clear that to reduce delay, metering should increase the rates at which commuters exit the freeway. The scheme critiqued here, as well as other well-known metering algorithms, are shown to have deficiencies in this, particularly when the freeway is plagued by a diverge bottleneck with a congested off-ramp. Other more effective schemes for reducing the delay caused by these...

Pattern Recognition for Curb Usage

Arcak, Murat PhD
Kurzhanskiy, Alex A., PhD
2024

The increasing use of transportation network companies and delivery services has transformed the utilization of curb space, resulting in a lack of parking and contributing to congestion. No systematic method exists for identifying curb usage patterns, but emerging machine learning technologies and low-tech data sources, such as dashboard cameras mounted on vehicles that routinely travel the area, have the potential of monitoring curb usage. To demonstrate how video data can be used to recognize usage patterns, we conducted a case study on Bancroft Way in Berkeley, CA. The project collected...

Vehicle-Actuated Control of a Diamond Interchange

Newell, Gordon F.
1998

We present here a vehicle-actuated traffic signal control scheme for a simple geometry of a diamond interchange. The scheme is guaranteed not to have blockage, to adjust automatically to changing flows and operate on a shorter mean cycle time than most fixed-time plans, at least during times of heavy traffic.

California’s Freeway Service Patrol Program: Management Information Systems Annual Report Fiscal Year 2015-2106

Mauch, Michael
Skabardonis, Alex
2017

The Freeway Service Patrol (FSP) is an incident management program implemented by Caltrans, the California Highway Patrol and local partner agencies to quickly detect and assist disabled vehicles and reduce non-recurring congestion along the freeway during peak commute hours. The first FSP program was piloted in Los Angeles, and was later expanded to other regions by state legislation in 1991. As of June 2016, there were fourteen participating FSP Programs operating in California, deploying over 340 tow trucks and covering over 1,800 (center-line) miles of congested California freeways....

Resource Allocation Algorithm for Multi-Vehicle Systems with Non holnomic Constraints

Rathinam, Sivakumar
Sengupta, Raja
Darbha, Swaroop
2005

Multi-vehicle systems are naturally encountered in civil and military applications. Cooperation amongst individual "miniaturized" vehicles allows for flexibility to accomplish missions that a single large vehicle may not readily be able to accomplish. While accomplishing a mission, motion planning algorithms are required to efficiently utilize a common resource (such as the total fuel in the collection of vehicles) or to penalize a collective cost function (such as to minimize the maximum time taken by the vehicles to reach their intended target). The objective of this paper is to present...