ITS Berkeley

Spatio-temporal Road Charge: A Potential Remedy for Increasing Local Streets Congestion

Bayen, Alexandre M.
Forscher, Teddy
2017

US population. Additionally, the emergence of large ridesourcing or transportation network companies (TNCs) totaling up to tens of thousands of registered drivers in single cities (all using the same routing app), there is further consolidation. Across the US, this has led to new or increased congestion patterns that are progressively asphyxiating local streets due to so-called “cut-through traffic.” As neighborhoods have started to realize this, private citizens have begun to resist, by trying to sabotage or trick the apps, or shaming the through traffic through opinion articles, and news...

Privacy-Preserving MaaS Fleet Management

Belletti, Francois
Bayen, Alexandre M.
2017

On-demand traffic fleet optimization requires operating Mobility as a Service (MaaS) companies such as Uber, Lyft to locally match the offer of available vehicles with their expected number of requests referred to as demand (as well as to take into account other constraints such as driver’s schedules and preferences). In the present article, we show that this problem can be encoded into a Constrained Integer Quadratic Program (CIQP) with block independent constraints that can then be relaxed in the form of a convex optimization program. We leverage this particular structure to yield a...

Traffic State Estimation on Highway: A Comprehensive Survey

Seo, Toru
Bayen, Alexandre
Kusakabe, Takahiko
Asakura, Yasuo
2017

Traffic state estimation (TSE) refers to the process of the inference of traffic state variables (i.e., flow, density, speed and other equivalent variables) on road segments using partially observed traffic data. It is a key component of traffic control and operations, because traffic variables are measured not everywhere due to technological and financial limitations, and their measurement is noisy. Therefore, numerous studies have proposed TSE methods relying on various approaches, traffic flow models, and input data. In this review article, we conduct a survey of highway TSE methods, a...

A Mathematical Framework for Delay Analysis in Single Source Networks

Samaranayake, Samitha
Parmentier, Axel
Xuan, Ethan
Bayen, Alexandre
2017

This article presents a mathematical framework for modeling heterogeneous flow networks with a single source and multiple sinks with no merging. The traffic is differentiated by the destination (i.e. Lagrangian flow) and different flow groups are assumed to satisfy the first-in-first-out (FIFO) condition at each junction. The queuing in the network is assumed to be contained at each junction node and spill-back to the previous junction is ignored. We show that this model leads to a well-posed problem for computing the dynamics of the system and prove that the solution is unique through a...

Intelligent Transportation Systems and Infrastructure A Series of Briefs for Smart Investments

Bayen, Alexandre M.
Shastry, Shankar
2017

The last decade has witnessed an unprecedented convergence of communication, control, and sensing that can potentially transform transportation infrastructure and delivery. At the most basic level, efficient operation and maintenance of our nation’s transportation infrastructure requires real time data exchange provided by intelligent transportation system technology. When implemented, these technologies have the potential to revolutionize the nation’s economic vitality by moving people and goods more quickly, efficiently, safely, and at lower cost to consumers.

Regularity and Lyapunov Stabilization of Weak Entropy Solutions to Scalar Conservation Laws

Blandin, Sébastien
Litrico, Xavier
Delle Monache, Maria
Piccoli, Benedetto
Bayen, Alexandre
2017

We consider the problem of Lyapunov boundary stabilization of the weak entropy solution to a scalar conservation law with strictly convex flux in one dimension of space, around a uniform equilibrium. We show that for a specific class of boundary conditions, the solution to the initial-boundary value problem for an initial condition with bounded variations can be approximated arbitrarily closely in the L1 norm by a piecewise smooth solution with finitely many discontinuities. The constructive method we present designs explicit boundary conditions in this class, which guarantee Lyapunov...

Random Projection Design for Scalable Implicit Smoothing of Randomly Observed Stochastic Processes

Belletti, Francois
Sparks, Evan
Bayen, Alexandre M.
Gonzalez, Joseph
2017

Sampling at random timestamps, long range dependencies, and scale hamper standard methods for multivariate time series analysis. In this paper we present a novel estimator for cross-covariance of randomly observed time series which unravels the dynamics of an unobserved stochastic process. We analyze the statistical properties of our estimator without needing the assumption that observation timestamps are independent from the process of interest and show that our solution is not hindered by the issues affecting standard estimators for cross-covariance. We implement and evaluate our...

MOBILITY21: Strategic Investments for Transportation Infrastructure & Technology

Mangharam, Rahul
Reyerson, Megan
Viscelli, Steve
Balakrishanan, Hamsa
Bayen, Alexandre
2017

America's transportation infrastructure is the backbone of our economy. A strong infrastructure means a strong America - an America that competes globally, supports local and regional economic development, and creates jobs. Strategic investments in our transportation infrastructure are vital to our national security, economic growth, transportation safety and our technology leadership. This document outlines critical needs for our transportation infrastructure, identifies new technology drivers and proposes strategic investments for safe and efficient air, ground, rail and marine mobility...

Integration of Information Patterns in the Modeling and Design of Mobility Management Services

Keimer, Alexander
Laurent-Brouty, Nicolas
Farokhi, Farhad
Signargout, Hippolyte
Cvetkovic, Vladimir
Bayen, Alexandre M.
Johansson, Karl H.
2017

Over the last decade, the rise of the mobile internet and the usage of mobile devices has enabled ubiquitous traffic information. With the increased adoption of specific smartphone applications, the number of users of routing applications has become large enough to disrupt traffic flow patterns in a significant manner. Similarly, but at a slightly slower pace, novel services for freight transportation and city logistics improve the efficiency of goods transportation and change the use of road infrastructure. The present article provides a general four-layer framework for modeling these new...

Traffic State Estimation Method with Efficient Data Fusion Based on the Aw-Rascle-Zhang Model

Seo, Toru
Bayen, Alexandre M.
2017

Higher-order traffic flow models describe the dynamics of non-equilibrium traffic (e.g., capacity drop, traffic oscillation). Therefore, a traffic state estimation (TSE) method based on higher-order models could have notable advantages over conventional method based on an equilibrium (first-order) model. First, they can encompass non-equilibrium traffic phenomena inherent to the nonlinearity of traffic flow. Second, they can directly fuse heterogeneous traffic data, such as flow measured by detectors and speed measured by probe vehicles. These features would be useful for large volumes of...