ITS Berkeley

Assessing the Functionality of Transit and Shared Mobility Systems after Earthquakes

Soga, Kenichi, PhD
Comfort, Louise, PhD
Zhao, Bingyu, PhD
Tang, Yili (Kelly), PhD
Han, Tianyu
2024

Located within the seismically active Pacific Ring of Fire, California's transportation infrastructure, especially in the Bay Area, is susceptible to earthquakes. A review of current research and stakeholder interviews revealed a growing awareness of emergency preparedness among local jurisdictions and transit agencies in recent years. However, many have yet to formalize and publish their recovery plans. This study introduces an agent-based multimodal transportation simulation tool to enhance post-earthquake transportation resilience. Integrating a road network simulator with a metro...

Environmental Justice & Transportation: A Citizen's Handbook

Cairns, Shannon
Greig, Jessica
Wachs, Martin
2003

Environmental justice is an increasingly important element of policy making in transportation. It is not specific to any mode of transportation, particular community, or single policy issue. It is fundamentally about fairness toward the disadvantaged and often addresses the exclusion of racial and ethnic minorities from decision making. The federal government has identified environmental justice as an important goal in transportation, and local and regional governments must incorporate environmental justice into transportation programs. Because ideas about justice differ between...

A Variable Formulation of Kinematic Waves: Solution Methods

Daganzo, Carlos F.
2003

This paper presents improved solution methods for kinematic wave trafficc problems with concave flow-density relations. As explained in part I of this work, the solution of a kinematic wave problem is a set of continuum least-cost paths in space-time. The least cost to reach a point is the vehicle number. The idea here consists in overlaying a dense but discrete network with appropriate costs in the solution region and then using a shortest-path algorithm to estimate vehicle numbers. With properly designed networks, this procedure is more accurate than existing methods and can be applied...

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...

Crane Double Cycling in Container Ports: Affect on Ship Dwell Time

Goodchild, Anne V.
Daganzo, Carlos F.
2005

Loading ships as they are unloaded (double-cycling) can improve the efficiency of a quay crane and thus container port. This paper describes the double-cycling problem, and presents two solution algorithms and simple formulae to estimate reductions in the number of operations, and operating time. The problem is formulated as a scheduling problem. Small problems can be solved to optimality with a standard numerical solver, but problems of typical size are computationally burdensome and terminated after 10 hours with optimality gaps larger than 50%. A formula for an improved lower bound to...

Enriching Sustainable Transport Decisions: Inputs from Operations Research and the Management Sciences

Wellar, Barry
Garrison, William
2009

Findings from the 2008-2009 Transport Canada project, Methodologies for Identifying and Ranking Sustainable Transport Practices in Urban Regions (Wellar, 2008d) reveal that the research methodologies, methods, and techniques from a number of disciplines apply to the process of making decisions about sustainable transport practices. Evidence in that regard is provided by: 1) the results of keyword-based literature searches; 2) the responses of municipal governments to a survey on the methodologies, methods, and techniques that are used; and 3), the commentaries of experts on the methods and...

Some Properties of Decentralized Supply Chains

Ouyang, Yanfeng
Daganzo, Carlos F.
2005

This paper analyzes the bullwhip effect in decentralized, linear and time-invariant (LTI) supply chains. It generalizes existing results by broadening the class of policies and customer demand processes under consideration. The supply chain is modeled as a single-input, singleoutput control system driven by arbitrary demands. The paper discusses the appropriateness of various metrics for the bullwhip effect, and derives analytical conditions to predict its presence independently of the demand process. The paper also gives a formula for the variance of the order stream at any stage when the...

A Variational Formulation for a Class of First Order PDE's

Daganzo, Carlos F.
2003

This paper proves that a class of first order partial differential equations, which include scalar conservation laws with concave (or convex) equations of state as special cases, can be formulated as calculus of variations problems. Every well-posed problem of this type, no matter how complicated, even in multi-dimensions, is reduced to the determination of a tree of shortest paths in a relevant region of space-time where "cost" is predefined. Thus, problems of this type can be practically solved with fast network algorithms. The new formulation automatically identifies the unique, single-...

Historical Transportation Development

Garrison, William L.
2003

The main tasks for this overview of transportation development are the provision and interpretation of information on the unfolding of the transportation systems. What have been the processes at work? What explains the similarities and differences from here to there and among systems? Big questions! But they are eased by ways systems are products of experiences, as will be seen when the paragraphs immediately following summarize early experiences. Life support systems, sustainability, and social development topics will be mentioned. After examining their immediate precursors, the...

Assessing URET Benefits for Airspace Users: A Quasi-Experimental Approach

Bolic, Tatjana
Hansen, Mark
2002

Air traffic control organizations around the world are trying to develop automation tools to help controllers manage increasing workload and to enable user preferred routes. This paper focuses on such a tool: User Request Evaluation Tool (URET), which is a decision-support tool for en-route controllers. URET is a prototype of an automated conflict probe. Based on flight plans and actual radar tracks, the URET system models aircraft trajectories and predicts possible conflicts. It also enables controllers to check clearances for conflicts prior to their issuance. This tool is intended as a...