ITS Berkeley

Unified Automatic Control of Vehicular Systems with Reinforcement Learning

Yan, Zhongxia
Kreidieh, Abdul Rahman
Vinitsky, Eugene
Bayen, Alexandre M.
2023

Emerging vehicular systems with increasing proportions of automated components present opportunities for optimal control to mitigate congestion and increase efficiency. There has been a recent interest in applying deep reinforcement learning (DRL) to these nonlinear dynamical systems for the automatic design of effective control strategies. Despite conceptual advantages of DRL being model-free, studies typically nonetheless rely on training setups that are painstakingly specialized to specific vehicular systems. This is a key challenge to efficient analysis of diverse vehicular and...

Urban Containment Policies and Physical Activity: A Time–Series Analysis of Metropolitan Areas, 1990–2002

Aytur, SA
Rodriguez, DA
Evenson, KR
Catellier, DJ
2008
Urban containment policies attempt to manage the location, character, and timing of growth to support a variety of goals such as compact development, preservation of greenspace, and efficient use of infrastructure. Despite prior research evaluating the effects of urban containment policies on land use, housing, and transportation outcomes, the public health implications of these policies remain unexplored. This ecologic study examines relationships among urban containment policies, state adoption of growth-management legislation, and population levels of leisure and transportation-related...

Uncovering Physical Activity Trade-Offs in Transportation Policy: A Spatial Agent-Based Model of Bogotá, Colombia

Stankov, I
Meisel, JD
Sarmiento, OL
Delclòs-Alió, X
Hidalgo, D
Guzman, L
Rodriguez, D
Hammond, R
Roux, AV Diez
2024

Transportation policies can impact health outcomes while simultaneously promoting social equity and environmental sustainability. We developed an agent-based model (ABM) to simulate the impacts of fare subsidies and congestion taxes on commuter decision-making and travel patterns. We report effects on mode share, travel time and transport-related physical activity (PA), including the variability of effects by socioeconomic strata (SES), and the trade-offs that may need to be considered in the implementation of these policies in a context with high levels of necessity-based physical...

The Value of Runway Time Slots for Airlines

Cao, Jia-ming
Kanafani, Adib
1997

In flight scheduling, airlines usually determine optimal timing for their flights to respond to time-dependent demand and the requirement of frequency plans, of available fleets and of aircraft routings. Nevertheless, it is unavoidable that some flights cannot actually operate at their expected time because of the capacity limit of the airport runway. Thus, adjustments have to be mad by altering some flights from their optimal times. Scarce runway time slots represent a resource whose value to the airline may be determined from the impact of such re-scheduling on the objective function of...

The Ridership Performance of the Built Environment for BRT Systems: Evidence from Latin America

Vergel-Tovar, C.
Rodriguez, D
2018
Despite the increasing popularity of BRT worldwide, there is a lack of empirical evidence regarding the built environment characteristics that determine BRT ridership. We examine associations between BRT station level demand and built environment attributes for 120 stations in seven Latin American cities. Using direct ridership models, we study whether underlying built environment factors identified using factor analysis and the package of these factors embodied in station “types” identified using cluster analysis were associated with higher ridership. Of the nine factors identified, those...

Identifying Density-Flow Relations on Arterial Surface Streets

Ahn, Soyoung
Cassidy, Michael J.
2002

A simple car-following rule was verified by studying vehicles discharging from long queues at signalized intersections. These observations indicated that the time-space trajectory of a jth vehicle discharging on a homogeneous intersection approach was essentially the same as the j−1th vehicle except for a translation in space and time. This is in agreement with a simplified theory proposed by G.F. Newell. The finding indicates that the congested branch of a density-flow curve is linear in form.

Transportation Periodicals and Newsletters Currently Received at the Institute of Transportation Studies Library, University of California at Berkeley

Hernandez, Paul A.
2000

This publication is intended to serve as a convenient reference to selected transportation periodicals and newsletters currently (2000) received by UC Berkeley's Harmer E. Davis Transportation Li-brary. This latest version of Transportation Periodicals and Newsletters represents a thourough revision of earlier editions (1989, 1993, and 1995) published under the same (or similar) title. The subject content of this listing reflects the subject strengths of the H.E. Davis Transportation Library: highways and traffic, air transportation, railroads, and urban transit. Water and pipeline modes...

Transportation Models in the Policy-Making Process: Uses, Misuses, and Lessons for the Future

Brinkman, Anthony
Goldman, Todd
1998

Panel 1. This session set the stage for the conference by examining some of the overarching issues in transportation modeling. Martin Wachs spoke about the promise and limitation of models from an ethical frame of reference. Genevieve Giuliano followed with an examination of how some of the changes underway in society may limit the ability to produce useful transportation forecasts. Finally, Larry Dahms commented from the perspective of an agency that operates within the policy-making process. Panel 2. The aim of this session was to generate a discussion of ways to make better use of...

Transit-Based Smart Parking in the San Francisco Bay Area: An Assessment of User Demand and Behavioral Effects

Rodier, Caroline J.
Shaheen, Susan A.
Eaken, Amanda M.
2004

This paper presents early findings from an application of advanced parking technologies to increase effective parking capacity at a transit station during the first half of 2004 in the San Francisco Bay Area (CA). It begins with an extensive review of the literature related to transit-based smart parking management systems to illustrate the range of system configurations and their potential travel, economic, and environmental effects. Two important conclusions from this review are: (1) lack of parking spaces at transit stations may be a significant constraint to transit use and (2) pre-...

Traffic Flow and Capacity

Cassidy, Michael J.
Hall, Randolf W.
1999

The design of highways, runways, ports or any transportation facility is guided by knowledge and theory of the traffic streams they serve. A facility’s scale, its geometry and its control measures are selected to affect certain properties of its traffic, such as the travel delay, the separation between vehicles, etc. In the case of highway traffic, the emphasis of this chapter, these are usually properties that are collected from, or averaged over, some number of vehicles. This is because the behavior of one driver differs from that of another, sometimes in complicated or even unexpected...