Data

Improving the Traffic Census and Highway Performance Monitoring System (HPMS) Programs

Mauch, Michael, PhD
Skabardonis, Alex, PhD
2020

Between 2017 and 2019, California experienced a series of devastating wildfires that together led over one million people to be ordered to evacuate. Due to the speed of many of these wildfires, residents across California found themselves in challenging evacuation situations, often at night and with little time to escape. These evacuations placed considerable stress on public resources and infrastructure for both transportation and sheltering. In the face of these clear challenges, transportation and emergency management agencies across California have widely varying levels of preparedness...

Benchmarking “Smart City” Technology Adoption in California: An Innovative Web Platform for Exploring New Data and Tracking Adoption

Post, Alison, PhD
Ratan, Ishana
Hill, Mary
Huang, Amy
Soga, Kenichi, PhD
Zhao, Bingyu, 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 alternative service providers. This project developed an innovative user-friendly web interface for local and state policymakers that tracks and displays information on the adoption of such technologies in California across the policing, transportation, and water and wastewater sectors for a comprehensive set of local...

The Development Of An Accident Database To Structure Land Use Regulations In Airport Runway Approach Zones Part II

Cooper, Douglas L.
Chira-chavala, T.
1998

This report presents and describes the expanded database containing 873 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 scatter plots developed from the accident data points is presented in section 4. The purpose of these plots is to provide a picture of the...

The Transforming Transportation Ecosystem — A Call to Action

Macfarlane, Jane
2019

The transportation landscape is in transition. Rising congestion, failing infrastructure, changing behaviors, adapting to a more inclusive definition of mobility, the desire for cleaner and more efficient engines, and grappling with the role of autonomous vehicles and drones, to name just some of the factors, demands that we take a fresh approach to designing for mobility. Yet the rapid pace of technology development is creating emerging trends that are driving change faster than our ability to model, design, and manage them. This could potentially result in undesirable economic,...

New Data and Methods for Estimating Regional Truck Movements

Dion, Francois, PhD
Yang, Mingyuan
Patire, Anthony, PhD
2023

This report describes how current methods of estimating truck traffic volumes from existing fixed roadway sensors could be improved by using tracking data collected from commercial truck fleets and other connected technology sources (e.g., onboard GPS-enabled navigation systems and smartphones supplied by third-party vendors). Using Caltrans District 1 in Northern California as an example, the study first reviews existing fixed-location data collection capabilities and highlights gaps in the ability to monitor truck movements. It then reviews emerging data sources and analyzes the...

Empirical Study of Ramp Metering and Capacity

Cassidy, Michael J.
Rudjanakanoknad, Jittichai
2002

Traffic data near the junction of a single-lane on-ramp (with a ramp meter) and a three-lane freeway were measured for six weekdays during the rush and studied. On each of these days, the merge became a bottleneck with queue discharge rates that were substantially lower than the flows that had passed the merge prior to the bottleneck's activation. On some days, these earlier high flows persisted for many minutes. The bottleneck always occurred when inflows from the on-ramp surged in the presence of high flows arriving from the freeway. Often, the on-ramp surges persisted for no longer than...

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...