ITS Berkeley

A common behavioral assumption in the modeling of traffic networks is the user equilibrium. Since traffic volumes, resulting from the rational behavior of agents, are easily but sparsely observable, and delay functions are not directly observable, we present a mathematical program with equilibrium constraint (MPEC) framework to impute the delay functions and centrally control the system from partial observations of equilibria. We also develop a novel method for solving MPECs using multi-convex optimization. Our block descent method has an intuitive interpretation, and numerical experiments...

The number and heterogeneity of traffic sensors are steadily increasing. A large part of the emerging sensors are measuring point speeds or travel times and in order to make efficient use of this data, it is important to develop methods and frameworks for fusion of point speed and travel time measurements in real-time. The proposed method combines a macroscopic traffic model and a non-linear filter with a new measurement model for fusion of travel time observations in a system that uses the velocity of cells in the network as state vector. The method aims to improve the fusion efficiency,...

We develop a data driven, partial differential equation-ordinary differential equation model that describes the response of the carbon dioxide (CO2) dynamics inside a conference room, due to the presence of humans, or of a user-controlled exogenous source of CO2. We conduct three controlled experiments to develop and tune a model whose output matches the measured output concentration of CO2 inside the room, when known inputs are applied to the model. In the first experiment, a controlled amount of CO2 gas is released inside the room from a regulated supply, and in the second and third...

This article starts from the classical Aw–Rascle–Zhang (ARZ) model for freeway traffic and develops a spectral analysis of its linearized version. A counterpart to the Froude number in hydrodynamics is defined that enables a classification of the nature of vehicle traffic flow using the explicit solution resulting from the analysis. We prove that our linearization about an equilibrium is stable for congested regimes and unstable otherwise. NGSIM data for congested traffic trajectories is used so as to confront the linearized model's predictions to actual macroscopic behavior of traffic....