Intelligent Transportation Systems

iShake: Mobile Phones as Seismic Sensors -- User Study Findings

Ervasti, Mari
Dashti, Shideh
Reilly, Jack
Bray, Jonathan D.
Alexandre Bayen
2011

The "iShake" system uses smartphones as seismic sensors to measure and deliver ground motion intensity parameters produced by earthquakes more rapidly and accurately than currently possible. Shaking table tests followed by field trial with approximately 30 iShake users were implemented to evaluate the reliability of the phones as seismic monitoring instruments and the functionality of the iShake system. In addition, user experiences were investigated with 59 iShake users, who provided feedback through a mobile questionnaire. Research included participative planning with a focus group to...

Individual Speed Variance in Traffic Flow: Analysis of Bay Area Radar Measurements

Blandin, Sébastien
Salam, Amir
Alexandre Bayen
2012

The recent increase of mobile devices able to measure individual vehicles speed and position with high accuracy brings new opportunities to traffic engineers. The large amount of individual probe measurements allows the study of phenomena previously unobservable with conventional sensing technologies, and the design of novel traffic monitoring and control strategies. However, challenges inherent to the use of speed and location data arise. One of the main difficulties of measurements collected from individual vehicles lie in their ability to provide relevant information on the...

Arterial Travel Time Forecast with Streaming Data: A Hybrid Approach of Flow Modeling and Machine Learning

Hofleitner, Aude
Herring, Ryan
Alexandre Bayen
2012

This article presents a hybrid modeling framework for estimating and predicting arterial traffic conditions using streaming GPS probe data. The model is based on a well-established theory of traffic flow through signalized intersections and is combined with a machine learning framework to both learn static parameters of the roadways (such as free flow velocity or traffic signal parameters) as well as to estimate and predict travel times through the arterial network. The machine learning component of the approach uses the significant amount of historical data collected by the Mobile...

Providing In-Vehicle Soft Safety Alerts Using Mobile Millennium Data and Vehicle Event Information

Nowakowski, Christopher
Gupta, Somak Datta
Myers, Scott
Shladover, Steven
Alexandre Bayen
2012

The Mobile Millennium project provided a platform for aggregating traffic information across various sources, including infrastructure sensors, commercial data feeds, probe vehicles, and probe cell phones. The Networked Traveler project provided the California PATH instrumented research vehicle platform used to both deliver vehicle probe data back to the infrastructure and to generate Advanced Driver Assistance Systems (ADAS) alerts to the drivers of those vehicles. The main theme of this collaboration project was to demonstrate the potential to create Enhanced Probe Vehicles (EPVs) by...

Understanding Road Usage Patterns in Urban Areas

Wang. Pu
Hunter, Timothy
Alexandre Bayen
2012

In this paper, we combine the most complete record of daily mobility, based on large-scale mobile phone data, with detailed Geographic Information System (GIS) data, uncovering previously hidden patterns in urban road usage. We find that the major usage of each road segment can be traced to its own - surprisingly few - driver sources. Based on this finding we propose a network of road usage by defining a bipartite network framework, demonstrating that in contrast to traditional approaches, which define road importance solely by topological measures, the role of a road segment depends on...

Mobile Phone Based Drifting Lagrangian Flow Sensors

Beard, Jonathan
Weekly, Kevin
Oroza, Carlos
Tinka, Andrew
Alexandre Bayen
2012

Mobile phone based drifters offer distinct advantages over those using custom electronic circuit boards. They leverage the inexpensive and modern hardware provided by the mobile phone market to supply water resource scientists with a new solution to sensing water resources. Mobile phone based drifters strategically address in situ sensing applications in order to focus on the large scale use of mobile phones dealing with communications, software, hardware, and system reliability. We have demonstrated that a simple design of a drifter built around an Android phone robustly survives many...

Hybrid Traffic Data Collection Roadmap: Pilot Procurement of Third-Party Traffic Data

Alexandre Bayen
Sharafsaleh, Mohammad
Patire, Anthony D.
2013

This research investigates the feasibility and the business case for purchasing third‐party probe data and fusing it with Caltrans’ existing data for the purpose of estimating travel times. The intent was to demonstrate an efficient and cost-effective use of alternative traffic data sources to complement the detection systems currently installed and operated by Caltrans.

Cyber Security of Water SCADA Systems—Part I: Analysis and Experimentation of Stealthy Deception Attacks

Amin, Saurabh
Litrico, Xavier
Sastry, S. Shankar
Alexandre Bayen
2013

This brief aims to perform security threat assessment of networked control systems with regulatory and supervisory control layers. We analyze the performance of a proportional-integral controller (regulatory layer) and a model-based diagnostic scheme (supervisory layer) under a class of deception attacks. We adopt a conservative approach by assuming that the attacker has knowledge of: 1) the system dynamics; 2) the parameters of the diagnostic scheme; and 3) the sensor-control signals. The deception attack presented here can enable remote water pilfering from automated canal systems. We...

Design of a Network of Robotic Lagrangian Sensors for Shallow Water Environments with Case Studies for Multiple Applications

Oroza, Carlos
Tinka, Andrew
Wright, Paul K
Alexandre Bayen
2013

This article describes the design methodology for a network of robotic Lagrangian floating sensors designed to perform real-time monitoring of water flow, environmental parameters, and bathymetry of shallow water environments (bays, estuarine, and riverine environments). Unlike previous Lagrangian sensors which passively monitor water velocity, the sensors described in this article can actively control their trajectory on the surface of the water and are capable of inter-sensor communication. The addition of these functionalities enables Lagrangian sensing in obstacle-encumbered...

Autonomous River Navigation Using the Hamilton–Jacobi Framework for Underactuated Vehicles

Weekly, Kevin
Tinka, Andrew
Anderson, Leah
Alexandre Bayen
2014

The feasibility of drifter studies in complex and tidally forced water networks has been greatly expanded by the introduction of motorized floating sensors. This paper presents a method for such motorized sensors to accomplish obstacle avoidance and path selection using the solutions to Hamilton-Jacobi-Bellman-Isaacs (HJBI) equations. The method is then validated experimentally.