ITS Berkeley

Scalable Learning of Segment-Level Traffic Congestion Functions

Choudhury, Shushman
Kreidieh, Abdul Rahman
Tsogsuren, Iveel
Arora, Neha
Osorio, Carolina
Bayen, Alexandre M.
2024

We propose and study a data-driven framework for identifying traffic congestion functions (numerical relationships between observations of traffic variables) at global scale and segment-level granularity. In contrast to methods that estimate a separate set of parameters for each roadway, ours learns a single black-box function over all roadways in a metropolitan area. First, we pool traffic data from all segments into one dataset, combining static attributes with dynamic time-dependent features. Second, we train a feed-forward neural network on this dataset, which we can then use on any...

Modifying Adaptive Cruise Control Systems for String Stable Stop-and -Go Wave Control

Wu, Fangyu
Carpio, Joy
Bunting, Matthew
Nice, Matthew
Work, Daniel
Sprinkle, Jonathan M.
Lee, Jonathan
Hornstein, Sharon
Bayen, Alexandre M.
2024

This letter addresses the important issue of energy inefficiency and air pollution resulting from stop-and-go waves on highways by introducing a novel controller called the Attenuative Kerner's Model (AKM). The objective of AKM is to enhance an existing Adaptive Cruise Control (ACC) system to improve vehicle following in stop-and-go waves. It is designed as a hybrid controller that is compatible with a wide range of commercial vehicles equipped with ACC. The article demonstrates the local string stability of the controller. Next, it presents a comparative analysis of AKM against two...

The Benefits of Carpooling

Shaheen, Susan
Cohen, Adam
Bayen, Alexandre M.
2024

Carpooling allows travelers to share a ride to a common destination and can include several forms of sharing a ride, such as casual carpooling and real-time carpooling. Because carpooling reduces the number of automobiles needed by travelers, it is often associated with numerous societal benefitsincluding:1) reductions in energy consumption and emissions, 2) congestion mitigation, and 3) reduced parking infrastructure demand. In recent years, economic, environmental, and social forces coupled with technological innovations are encouraging shared and pooled services. Shared mobility is...

Pareto Control Barrier Function for Inner Safe Set Maximization Under Input Constraints

Cao, Xiaoyang
Fu, Zhe
Bayen, Alexandre M.
2024

This article introduces the Pareto Control Barrier Function (PCBF) algorithm to maximize the inner safe set of dynamical systems under input constraints. Traditional Control Barrier Functions (CBFs) ensure safety by maintaining system trajectories within a safe set but often fail to account for realistic input constraints. To address this problem, we leverage the Pareto multi-task learning framework to balance competing objectives of safety and safe set volume. The PCBF algorithm is applicable to high-dimensional systems and is computationally efficient. We validate its effectiveness...

Kernel-based Planning and Imitation Learning Control for Flow Smoothing in Mixed Autonomy Traffic

Fu, Zhe
Alanqary, Arwa
Kreidieh, Abdul Rahman
Bayen, Alexandre M.
2024

This article presents a new architecture for managing heterogeneous fleets aimed at achieving flow harmonization in mixed-autonomy traffic, demonstrating robustness across different sensing paradigms. We develop a kernel-based planning controller capable of providing anticipative coordination over low-bandwidth or high-latency networks. Furthermore, we employ a scenario-based optimization technique to tune the parameters of the proposed controller which offers performance improvement over the grid search technique across different simulation scenarios. Additionally, our architecture...

Improving Social Cost in Traffic Routing with Bounded Regret via Second-Best Tolls

Alanqary, Arwa
Kreidieh, Abdul Rahman
Samitha Samaranayake
Bayen, Alexandre M.
2024

In this work, we investigate algorithmic improvements that navigation services can implement to steer road networks toward a system-optimal state while retaining high levels of user compliance. We model the compliance of users using marginal regret, and we extend the definition of the social cost function to account for various traffic congestion externalities. We propose a routing algorithm for the static traffic assignment problem that improves the social cost with guarantees on the worst-case regret in the network. This algorithm leverages the connection we establish between this...

Stability of Ring Roads and String Stability of Car Following Models

Chou, Fang-Chieh
Keimer, Alexander
Bayen, Alexandre M.
2024

The ring road, a closed circular track, provides a controlled environment for studying car-following behavior in dynamic traffic flow. This work examines the ring road from a stability analysis perspective to shed light on its underlying stability mechanisms. We model the ring road as an interconnected system composed of subsystems of ODEs which can represent car-following dynamics. We analyze its stability based on the string stability of these subsystems and then apply the findings to ring road models. Our study addresses both interconnected systems consisting of homogeneous (identical)...

Design, Preparation, and Execution of the 100-AV Field Test for the CIRCLES Consortium: Methodology and Implementation of the Largest Mobile Traffic Control Experiment to Date

Ameli, Mostafa
McQuade, Sean T.
Lee, Jonathan W.
Bunting, Matthew
Nice, Matthew
Wang, Han
Barbour, William
Weightman, Ryan J.
Denaro, Christopher
Delorenzo, Ryan
Hornstein, Sharon
Davis, Jon F.
Timsit, Dan
Wagner, Riley
Xu, Ruotong
Mahmood, Malaika
Mahmood, Mikail
Monache, Maria Laura Delle
Seibold, Benjamin
Work, Daniel
Sprinkle, Jonathan M.
Piccoli, Benedetto
Bayen, Alexandre M.
2025

This article presents the comprehensive design, setup, execution, and evaluation of the MegaVanderTest (MVT) experiment conducted by the Congestion Impacts Reduction via CAV-in-the-Loop Lagrangian Energy Smoothing (CIRCLES) Consortium, which aimed to mitigate traffic congestion using partially autonomous vehicles (AVs) (see “Summary”). The experiment involved 100 vehicles on Nashville’s Interstate 24 (I-24) highway, utilizing various control algorithms to smooth stop-and-go traffic waves. The execution of the MVT experiment required a coordinated effort from multiple teams. This article...

Traffic Smoothing Using Explicit Local Controllers: Experimental Evidence for Dissipating Stop-and-go Waves with a Single Automated Vehicle in Dense Traffic

Hayat, Amaury
Alanqary, Arwa
Bhadani, Rahul
Denaro, Christopher
Weightman, Ryan J.
Xiang, Shengquan
Lee, Jonathan W.
Bunting, Matthew
Gollakota, Anish
Nice, Matthew
Gloudemans, Derek A.
Zachár, Gergely
Davis, Jon F.
Delle Monache, Maria
Seibold, Benjamin
Bayen, Alexandre
Sprinkle, Jonathan M.
Work, Daniel B.
Piccoli, Benedetto
2025

This article presents experimental evidence of the ability of a single automated vehicle acting as a controller to effectively dissipate stop-and-go waves in real traffic. The automated vehicle succeeded in stabilizing the speed profile by reducing oscillations in time and speed variations between vehicles during rush hour on I-24 in the Nashville area. We detail the control design, deployment and results obtained in this experiment, conducted as part of the CIRCLES consortium’s “MegaVanderTest” 2022, which involved a total of 100 automated vehicles.

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
Sprinkle, Jonathan M.
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...