Modeling

Reducing Detailed Vehicle Energy Dynamics to Physics-Like Models

Khoudari, Nour
Almatrudi, Sulaiman
Ramadan, Rabie
Carpio, Joy
Yao, Mengsha
Butts, Kenneth
Bayen, Alexandre M.
2023

The energy demand of vehicles, particularly in unsteady drive cycles, is affected by complex dynamics internal to the engine and other powertrain components. Yet, in many applications, particularly macroscopic traffic flow modeling and optimization, structurally simple approximations to the complex vehicle dynamics are needed that nevertheless reproduce the correct effective energy behavior. This work presents a systematic model reduction pipeline that starts from complex vehicle models based on the Autonomie software and derives a hierarchy of simplified models that are fast to evaluate,...

From Sim to Real: A Pipeline for Training and Deploying Traffic Smoothing Cruise Controllers

Lichtle, Nathan
Vinitsky, Eugene
Nice, Matthew
Bhadani, Rahul
Bunting, Matthew
2024

Designing and validating controllers for connected and automated vehicles to enhance traffic flow presents significant challenges, from the complexity of replicating real-world stop-and-go traffic dynamics in simulation, to the intricacies involved in transitioning from simulation to actual deployment. In this work, we present a full pipeline from data collection to controller deployment. Specifically, we collect 772 km of driving data from the I-24 in Tennessee, and use it to build a one-lane simulator, placing simulated vehicles behind real-world trajectories. Using policy-gradient...

Car-Following Models: A Multidisciplinary Review

Zhang, Tianya Terry
Jin, Peter J.
McQuade, Sean T.
Bayen, Alexandre
Piccoli, Benedetto
2024

Car-following (CF) algorithms are crucial components of traffic simulations and have been integrated into many production vehicles equipped with Advanced Driving Assistance Systems (ADAS). Insights from the model of car-following behavior help researchers to understand the causes of various macro phenomena that arise from interactions between pairs of vehicles. Car-following Models encompass multiple disciplines, including traffic engineering, physics, dynamic system control, cognitive science, machine learning, deep learning, and reinforcement learning. This paper presents an extensive...

Modeling, Monitoring, and Controlling Road Traffic Using Vehicles to Sense and Act

Monache, Maria Laura Delle
McQuade, Sean T.
Matin, Hossein Nick Zinat
Gloudemans, Derek A.
Wang, Yanbing
Gunter, George L.
Bayen, Alexandre M.
Lee, Jonathan W.
Piccoli, Benedetto
Seibold, Benjamin
Sprinkle, Jonathan M.
Work, Daniel B.
2025

This review offers a comprehensive overview of current traffic modeling, estimation, and control methods, along with resulting field experiments. It highlights key developments and future directions in leveraging technological advancements to improve traffic management and safety. The focus is on macroscopic, microscopic, and micro-macro models, as well as state-of-the-art control techniques and estimation methods for deploying vehicles in traffic field experiments.

Reevaluating Policy Gradient Methods for Imperfect-Information Games

Rudolph, Max
Lichtle, Nathan
Mohammadpour, Sobhan
Bayen, Alexandre
Kolter, J. Zico
Zhang, Amy
Farina, Gabriele
Vinitsky, Eugene
Sokota, Samuel
2025

In the past decade, motivated by the putative failure of naive self-play deep reinforcement learning (DRL) in adversarial imperfect-information games, researchers have developed numerous DRL algorithms based on fictitious play (FP), double oracle (DO), and counterfactual regret minimization (CFR). In light of recent results of the magnetic mirror descent algorithm, we hypothesize that simpler generic policy gradient methods like PPO are competitive with or superior to these FP, DO, and CFR-based DRL approaches. To facilitate the resolution of this hypothesis, we implement and release the...

Validation and Calibration of Energy Models with Real Vehicle Data from Chassis Dynamometer Experiments

Carpio, Joy
Almatrudi, Sulaiman
Khoudari, Nour
Fu, Zhe
Butts, Kenneth
Lee, Jonathan
Seibold, Benjamin
Bayen, Alexandre
2025

Accurate estimation of vehicle fuel consumption typically requires detailed modeling of complex internal powertrain dynamics, often resulting in computationally intensive simulations. However, many transportation applications-such as traffic flow modeling, optimization, and control-require simplified models that are fast, interpretable, and easy to implement, while still maintaining fidelity to physical energy behavior. This work builds upon a recently developed model reduction pipeline that derives physics-like energy models from high-fidelity Autonomie vehicle simulations. These reduced...

Evaluating the Capacity of Freeway Weaving Sections

Wang, Mu-han
Cassidy, Michael J.
Chan, Patrick
May, Adolf D.
1993

The research described in this paper employed simulation modeling and empirical observations in an effort to: (1) Identify the traffic flow phenomena that characterize freeway weaving section capacity; and (2) determine appropriate traffic flow rate values that reflect weaving section capacity. The INTRAS microscopic simulation model was calibrated and validated using empirical data collected at a weaving site. Increasing traffic demands were then sequentially input into repeated simulation runs to identify the boundary between uncongested and congested operation. Where a weaving...

An Electronic Surveillance and Control System for Traffic Management on the Borman Expressway. Part II, Calibrating a Simulation Model

Wang, Mu-Han
Cassidy, Michael J.
1995

This report presents a project whose purpose was to calibrate a freeway simulation model to emulate traffic operating conditions on the Borman Expressway. The computer simulation model can then be used to predict impacts created by a host of possible conditions including incident occurrences, maintenance, reconstruction and the deployment of various freeway control and management strategies. The results of the simulation model can be used as a decision-making tool for adopting suitable policies to address operating needs.

Application of Ordered Probit Techniques to Analyze Ratings of Blissymbol Complexity

Soto, Gloria
Cassidy, Michael
Madanat, Samer
1996

This paper explores the application of ordered probit modeling, an econometric technique commonly used for the analysis of rating data in situations when respondents are asked to rate items (e.g., an object, service, or product), one at a time. To demonstrate the application of this methodology, an existing data set, originally collected to measure the perceived complexities for an array of Blissymbols, was used. Findings from the use of the ordered probit model are compared with those resulting from the earlier research that used regression procedures. Results from the use of ordered...

Middleware for Cooperative Vehicle-Infrastructure Systems

Manasseh, Christian
Sengupta, Raja
2008

Middleware has emerged as an important architectural component in supporting distributed applications. The role of middleware is to present a unified programming model to application writers and to mask out problems of heterogeneity and distribution. Mobile sensors fall into the space of distributed systems that suffer from isolated data sources, heterogeneous communication infrastructure and varying application requirements. In this report, we provide a middleware architecture that addresses the needs of a distributed system made of mobile sensors in general and discuss the implementation...