ITS Berkeley

Multi-Directional Continuous Traffic Model for Large-scale Urban Networks

Tumash, Liudmila
Canudas-de-Wit, Carlos
2022

In this paper, we propose a new multi-directional two-dimensional continuous model for urban traffic. It is called the NEWS model, since it represents a system of four partial differential equations (PDEs) that describe propagation of vehicle density in cardinal direction layers: North, South, West and East. The NEWS model can be applied to predict traffic evolution on a general urban network of arbitrary size by knowing only its boundary flows, as well as its topology and infrastructure parameters such as roads speed limits, number of lanes and capacities. The flux direction is retrieved...

Multi-stage Models for Dynamic Ride-Sharing in Taxi Services and Congestion Analysis

Quadrifoglio, Luca
Zhang, Cheng
Sun, Min-Ci
Delle Monache, Maria Laura
Yeo, Yuneil
2024

This research introduces practical optimization model for implementing ride-sharing in taxi services and studies the effects of ride-sharing on the congestion status through the case study of Chicago. Ride-sharing combines trips into one ride-shared trip with the objective of maximizing the total mileage saving. This research proposes a multi-stage model to optimize rider matches, aiming to reduce the total travel distance and enhance the matching of multiple riders. To validate the effectiveness of the model, real taxi data from Chicago is used, demonstrating significant improvements in...

Near Collision and Controllability Analysis of Nonlinear Optimal Velocity Follow-the-Leader Dynamical Model In Traffic Flow

Matin, Hossein Nick Zinat
Delle Monache, Maria Laura
2023

This paper examines the optimal velocity follow-the-leader dynamics, a microscopic traffic model, and explores different aspects of the dynamical model, with particular emphasis on collision analysis. More precisely, we present a rigorous boundary-layer analysis of the model which provides a careful understanding of the behavior of the dynamics in trade-off with the singularity of the model at collision.

Intelligent Transport Systems

Deakin, Elizabeth
Frick, Karen Trapenberg
Skabardonis, Alexander
2009

If you've seen an electronic message sign alongthehighwaythattells you how long it will take to get downtown or to the airport, or paid your toll or your parking fees with an electronic tag, or ridden a bus that triggered the traffic lights to turn green as it approached them, then you have experienced some of the benefits of Intelligent Transportation Systems (ITS)—an...

New Frontiers of Freeway Traffic Control and Estimation

Delle Monache, M. L.
Pasquale, C.
Barreau, M.
Stern, R.
2022

This article provides an overview of the classical and new techniques in traffic flow control and estimations. The overview begins with a description of the most used traffic flow models for estimation and control. Then, it shifts towards using those models for traffic flow estimation using physics-informed machine learning techniques. Lastly, it focuses on traffic flow control describing the most classical techniques and the new advancement in traffic control using autonomous vehicles.

Nonlinear Advection-Diffusion Models of Traffic Flow: a Numerical Study

Matin, Hossein Nick Zinat
Do, Dawson
Monache, Maria Laura Delle
2023

The first-order degenerate parabolic traffic flow dynamics are the simplest extension of the Lighthill, Whitham, and Richards (LWR) model which aim at correcting the discrepancies between the LWR model and the observation collected from real data. In addition, the nonlinearity and degeneracy of these models are designed to address the fundamental criticism of linear diffusivelycorrected kinematic-wave models. While several first-order methods have been proposed in the literature, the predictive capabilities of these models has not been sufficiently studied with respect to real data. The...

On the Analytical Properties of a Nonlinear Microscopic Dynamical Model for Connected and Automated Vehicles

Matin, Hossein Nick Zinat
Yeo, Yuneil
Gong, Xiaoqian
Monache, Maria Laura Delle
2024

In this letter, we propose an integrated dynamical model of Connected and Automated Vehicles (CAVs) which incorporates CAV technologies and a microscopic car-following model to improve safety, efficiency, and convenience. We rigorously investigate the analytical properties such as well-posedness, maximum principle, perturbation, and stability of the proposed model in some proper functional spaces. Furthermore, we prove that the model is collision-free and derive an explicit lower bound on the distance as a safety measure.

On the Existence of Solution of Conservation Law with Moving Bottleneck and Discontinuity in FLux

Matin, Hossein Nick Zinat
Monache, Maria Laura Delle
2023

In this paper, a PDE-ODE model with discontinuity in the flux as well as a flux constraint is analyzed. A modified Riemann solution is proposed and the existence of a weak solution to the Cauchy problem is rigorously investigated using the wavefront tracking scheme.

Reinforcement Learning-based Adaptive Speed Controllers in Mixed Autonomy Condition

Wang, H.
Zinat Matin, H. Nick
Delle Monache, M. L.
2024

The integration of Automated Vehicles (AVs) into traffic flow holds the potential to significantly improve traffic congestion by enabling AVs to function as actuators within the flow. This paper introduces an adaptive speed controller tailored for scenarios of mixed autonomy, where AVs interact with human-driven vehicles. We model the traffic dynamics using a system of strongly coupled Partial and Ordinary Differential Equations (PDE-ODE), with the PDE capturing the general flow of human-driven traffic and the ODE characterizing the trajectory of the AVs. A speed policy for AVs is derived...

Reinforcement Learning-Based Oscillation Dampening: Scaling Up Single-Agent Reinforcement Learning Algorithms to a 100-Autonomous-Vehicle Highway Field Operational Test

Jang, Kathy
Lichtle, Nathan
Vinitsky, Eugene
Shah, Adit
Bunting, Matthew
Nice, Matthew
Piccoli, Benedetto
Seibold, Benjamin
Work, Daniel B.
Delle Monache, Maria Laura
Sprinkle, Jonathan
Lee, Jonathan W.
Bayen, Alexandre M.
2025

In this article, we explore the technical details of the reinforcement learning (RL) algorithms that were deployed in the largest field test of automated vehicles designed to smooth traffic flow in history as of 2023, uncovering the challenges and breakthroughs that come with developing RL controllers for automated vehicles. We delve into the fundamental concepts behind RL algorithms and their application in the context of self-driving cars, discussing the developmental process from simulation to deployment in detail, from designing simulators to reward function shaping. We present the...