Traffic Theory

Bi-Level Optimization Model for DTA Flow and Speed Calibration

Samaei, Maryam
Ameli, Mostafa
Davis, Jon F.
McQuade, Sean T.
Bayen, Alexandre M.
2024

Dynamic traffic assignment (DTA) models are capable of capturing traffic dynamics and are well-known as a critical tool in controlling and predicting the traffic situation Ameli (2019). DTA simulation allows us to measure the results of deploying different technologies and applying different policies along with real experiments Ameli et al. (2020); Chen et al. (2021); Balzer et al. (2023). One of the crucial steps to achieve realistic results from simulation tools is calibration. It aims to determine the DTA model’s input such that the output represents traffic scenarios with a reliable...

Eulerian Trilogy

Sun, Dengfeng
Yang, Samuel
Bayen, Alexandre M.
2012

Stability of Modified Max Pressure Controller with Application to Signalized Traffic Networks

Pumir, Thomas
Anderson, Leah
Bayen, Alexandre M.
2015

This work describes a type of distributed feedback control algorithm that acts on a vertical queueing network where flow dynamics may greatly outpace the rate of feedback and actuation. The modeled network has a known, finite set of feasible actuations for the binary controllers located at each network node. It also has known expected demands, split ratios, and maximum service rates. Previous work proposed the application of a max pressure controller to maximize throughput on such a network without the need for centralized computation of a control policy. Here we extend the max pressure...

Computation and Control of Solutions to the Burgers Equation Using Viability Theory

Aubin, J.-P.
Bayen, A.M.
Saint-Pierre, P.
2005

This paper presents a new approach which links the solution to the Burgers tracking problem to the concept of capture basin used in viability theory. This link enables the proof of the existence and uniqueness of the solution of the Burgers tracking problem. The Burgers tracking problem is linked to the Frankowska solutions of the Burgers equation. These results are easily extended to any first order hyperbolic partial differential equation (PDE) written in conservation law form, which is illustrated with the famous Lighthit-Whitham-Richards (LWR) PDE, known in highway traffic theory. The...

MILP Control of Aggregate Eulerian Network Airspace Models

Robelin, C.-A.
Sun, Dengfeng
Wux, Guoyuan
Bayen, Alexandre M.
2006

A new Eulerian model of airspace is derived and applied to high altitude traffic for a full air traffic control center of the National Airspace System. The Eulerian model is reduced to a linear time invariant dynamical system, in which the state is a vector of aggregate aircraft counts. The model is validated against ASDI data and applied to the Oakland airspace. The problem of controlling sector aircraft count is posed as an integer program, in which the dynamical system appears in the constraints. To improve the computational time of calculating the solution, the integer program is...

Adjoint-based Control of a New Eulerian Network Model of Air Traffic Flow

Bayen, A.M.
Raffard, R.L.
Tomlin, C.J.
2006

An Eulerian network model for air traffic flow in the National Airspace System is developed and used to design flow control schemes which could be used by Air Traffic Controllers to optimize traffic flow. The model relies on a modified version of the Lighthill-Whitham-Richards (LWR) partial differential equation (PDE), which contains a velocity control term inside the divergence operator. This PDE can be related to aircraft count, which is a key metric in air traffic control. An analytical solution to the LWR PDE is constructed for a benchmark problem, to assess the gridsize required to...

Continuous Adjoint Method for Air Traffic Flow Management

Strub, Issam S.
Bayen, Alexandre M.
2006

This article develops a model of air traffic flow using an Eulerian description with hyperbolic partial differential equations. Existence and uniqueness (well-posedness) of a solution to the system of partial differential equations on a network is established. Subsequently, an optimal control problem is studied with the junction coefficients as control variables. We use a continuous adjoint approach and we implement it on a network with 16 links and 5 junctions, demonstrating the computational efficiency of this method