ITS Berkeley

Spatiotemporal Studies of Traffic Phenomenon on Freeways with Limited-access Special Lanes

Cassidy, Michael J.
Kim, Kwangho
2015

Most special-use freeway lanes in the US, whether reserved for carpools, toll-paying commuters or both, are physically separated from the adjacent regular-use lanes by some form of barrier. Vehicle movements in and out of a special lane of this type are permitted only at select access points along the route. The barrier at each select point might open for a distance of 400 m or so. Limiting access in this way is said to reduce the “turbulence” that might otherwise occur were the special lane not to have a buffer, such that vehicles could instead enter or exit that lane anywhere along its...

California’s Freeway Service Patrol Program:Management Information System Annual Report Fiscal Year 2018-19

Mauch, Michael
Skabardonis, Alex
2020

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 2018, there were fourteen participating FSP Programs operating in California, deploying 328 tow trucks and covering over 1,823 (centerline) miles of congested California freeways. The...

Vision-Based Following of Structures Using an Unmanned Aerial Vehicle (UAV)

Rathinam, Sivakumar
Kim, ZuWhan
Sengupta, Raja
2006

Inspecting and monitoring oil-gas pipelines, roads, bridges, canals are very important in ensuring the reliability and life expectancy of these civil systems. An autonomous Unmanned Aerial Vehicle (UAV) can decrease the operational costs, expedite the monitoring process and be used in situations where a manned inspection is not possible. This paper addresses the problem of monitoring these systems using an autonomous UAV based on visual feedback. A single structure detection algorithm that can identify and localize various structures including highways, roads, and canals is presented in...

Linkages Between Transportation Planning and the Environment

Wachs, Martin
1999

Transportation investments have historically been among society’s most important contributors to environmental improvement, but today transportation programs and projects are more often of concern as sources of major environmental problems. Over the past thirty years, since the enactment of the National Environmental Protection Act (NEPA) and the first Clean Air Act Amendments (CAAA), the relationship between transportation planning and environmental policy making has continuously become ever more complex and problematic. Until about 1835, when early public transport was just being...

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).

The Role of Intelligent Transportation Systems (ITS) in Intermodal Air Cargo Operations

Tsao, H.-S. Jacob
Rizwan, Asim
2001

This study examines the extent to which states have devolved one of the most fundamental decisions in transportation policy—whether to use taxation powers to fund transportation improvements—to local and regional governments. The purpose of the study is to generate a baseline of knowledge on “local option transportation taxes” in all fifty states, including the relevant legislative authority for these taxes, the extent to which local areas have adopted them, and the roles they play within their states’ overall transportation finance frameworks.

Local Option Transportation Taxes in the United States (Part Two: "State-by-State Findings")

Goldman, Todd
Corbett, Sam
Wachs, Martin
2001

This study examines the extent to which states have devolved one of the most fundamental decisions in transportation policy—whether to use taxation powers to fund transportation improvements—to local and regional governments. The purpose of the study is to generate a baseline of knowledge on “local option transportation taxes” in all fifty states, including the relevant legislative authority for these taxes, the extent to which local areas have adopted them, and the roles they play within their states’ overall transportation finance frameworks.

Causes And Effects Of Phase Transitions In Highway Traffic

Daganzo, C. F.
Cassidy, M. J.
Bertini, R. L.
1997

It is shown that all the phase transitions in and out of freely flowing traffic reported earlier for a German site could be caused by bottlenecks, as are all the transitions observed at two other sites examined here. Furthermore, all the evidence indicates that bottlenecks cause these transitions in a predictable way, and no evidence is found that stoppages (jams) appear spontaneously in free flow traffic for no apparent reason. The most salient phenomena observed at all locations are explained in terms of a simple theory specific to traffic.

A Behavioral Theory of Multi-Lane Traffic Flow Part II: Merges and the Onset of Congestion

Daganzo, Carlos F.
1999

This paper examines the behavior of multi-lane freeway traffic past on-ramps, building on the continuum model of part I and focusing on the onset of congestion. The main complication with merges is that rabbits (fast vehicles) entering from an on-ramp usually stay on the shoulder lane(s) of the freeway for some distance before merging into the fast lane(s). An idealization is proposed where this distance is taken to be the same for all vehicles. As a result, the system behaves as if there was a fixed buffer zone where entering rabbits cannot change lanes. The model of part I is extended to...

Tapping In: Leveraging Open-Loop Fare Payments to Increase Financial Inclusion

Broader, Jacquelyn
2024

In the United States, public transit agencies are increasingly growing interested in deploying open-loop payment systems for public transit fare payments. This interest is based on the benefits these systems can offer, from faster boarding times to the potential of attracting more riders. Open-loop fare payment systems’ popularity is evidenced by the growing number of American public transit agencies who have deployed them; most of whom (63%) are located in California. The overlap between public transit riders who are both transit-dependent and financially excluded (i.e., have no or...