Modeling

Integrating Traffic Network Analysis and Communication Network Analysis at a Regional Scale to Support More Efficient Evacuation in Response to a Wildfire Event

Soga, Kenichi
Comfort, Louise
Zhao, Bingyu
Lorusso, Paola
Soysal, Sena
2021

As demonstrated by the Camp Fire evacuation, communications (city-to-city, city-to-residents) play important roles in coordinating traffic operations and safeguarding region-wide evacuation processes in wildfire events. This collaborative report across multiple domains (fire, communication and traffic), documents a series of simulations and findings of the wildfire evacuation process for resource-strapped towns in Northern California. It consists of: (1) meteorological and vegetation-status dependent fire spread simulation (cellular automata model); (2) agency-level and agency-to-residents...

A Network Model of Departure Time Choice with Spillovers and Merging Effects. Part I: Building Block

Lago, Alejandro
Daganzo, Carlos F.
2003

This paper presents a departure-time user equilibrium model that explicitly considers the most important determinants of congestion behavior in cities during the morning commute: different commuter origins, merge interactions and queue spillovers. The proposed model combines three previous works: the departure-time equilibrium theory in Vickrey (1969), the traffic flow model of Newell (1993) and the merge theory in Daganzo (1996). The paper examines the simplest possible network exhibiting the three important features and discusses the ensuing policy implications. The solution algorithm...

On the Stability of Supply Chains

Daganzo, Carlos F.
2002

This paper examines the stability of autonomous supply chains. In an autonomous supply chain, suppliers only communicate with their downstream neighbor; i.e., their immediate customer. The inventory management policies used by the suppliers characterize a chain. An important property of a policy is its “gain”, which relates marginal changes in the average steady state inventory to small changes in the steady state demand rate. It is shown that all autonomous policies with positive gains are unstable when applied to a homogeneous supply chain if they do not use future order commitments....

Distributing Synchronous Programs Using Bounded Queues, a coordinated traffic signal application

Zennaro, Marco
Sengupta, Raja
2005

This paper is about the modular compilation and distribution of a sub-class of Simulink programs [10] across networks using bounded FIFO queues. The problem is first addressed mathematically. Then, based on these formal results, a software library for the modular compilation and distribution of Simulink program is given. The performance the library is given. The value of synchronous programming for the next generation of traffic control value is discussed. The adoption of these tools seems to be the natural candidate to address the needs of the traffic engineers. As a case study we present...

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...

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...

Wildfire Evacuation Planning Can Be Greatly Enhanced by Considering Fire Progression, Communication Systems, and Other Dynamic Factors

Soga, Kenichi, PhD
Comfort, Louise, PhD
Zhao, Bingyu, PhD
Lorusso, Paola, MSc
Soysal, sena
2021

Wildfires have become a perpetual crisis for communities across California. For life-threatening wildfires, mass evacuation often becomes the only viable option to protect lives. Yet, looking back at recent events, including the devastating 2018 Camp Fire in Northern California, there are significant challenges associated with the evacuation process, such as multi-agency coordination, agency-resident communication, and management of extraordinarily high amounts of traffic within a short period of time. Currently, emergency planners use evacuation models that are typically based on existing...

Climate Adaptation Strategies for California Airports will Require a Holistic Approach, Including New Governance Models

Lindbergh, Sarah, PhD
Reed, Jackson
Takara, Matthew
Aparri, Aidan
Rakas, Jasenka, PhD
2022

Airports are complex social, technical, and environmental systems. Understanding their complexity is fundamental for advancing transformative climate adaptation policy. For airports to adapt, climate science must be incorporated not only into standards of specific equipment and facilities, but also into the air traffic network and its interconnected infrastructure systems (e.g., road access, ground-based communications, navigation, and surveillance systems). In addition, airport adaptation requires a shift in the way policy is designed, reinforced, and updated, which in turn relies on an...

Distance-dependent Congestion Pricing for Downtown Zones

Daganzo, Carlos F
Lehe, Lewis J
2014

A growing literature exploits macroscopic theories of traffic to model congestion pricing policies in downtown zones. This study introduces trip length heterogeneity into this analysis and proposes a usage-based, time-varying congestion toll that alleviates congestion while prioritizing shorter trips. Unlike conventional trip-based tolls the scheme is intended to align the fees paid by drivers with the actual congestion damage they do, and to increase the toll’s benefits as a result. The scheme is intended to maximize the number of people that finish their trips close to their desired...

Some Properties of a Multi-Lane Extension of the Kinematic Wave Model

Laval, Jorge A.
2003

This paper extends an existing continuum multi-lane formulation for traffic flow, provides a discrete formulation for its numerical solution, and show initial results. The new formulation enables a natural treatment of boundary conditions such as merges, diverges, lane-drops and moving bottlenecks. The proposed model needs few extra parameters and is parsimonious. The look-ahead distance, for example, induces that non-local conditions affect the flow at any time-space point, causing smooth regime changes and fast waves. We find that as the look-ahead distance tends to zero, the solution...