PATH

A Field-Deployable Real-Time Laser-Based Non-Intrusive Detection System for Measurement of True Travel Time on the Highway

Cheng, Harry H.
Shaw, Ben
Palen, Joe
Wang, Zhaoqing
Chen, Bo
2002

In this research project we are developing a roadway detection system that can directly determineO/D data non-intrusively without violating the public's privacy (as in license plate recognitionsystems). While we have previously developed a real-time laser-based non-intrusive detectionsystem for measurement of true travel time on the highway, we improved the system further. Afeed-back loop, using microchip control, was introduced into the system. This makes the systemeasy to use. The mechanical components were also improved to increase the precision of thesystem. Software to display the...

A Vehicle Collision Model for Platoon Controller Development

Tongue, Benson H.
Packard, Andrew
Harriman, Douglas
1997

This is the final report of the research program “Compatibility of Vehicles Within a Platoon (MOU-156).” This research area is continuing under a different, contract and thus, although the work presented herein is complete unto itself, the overall research goals laid out at the beginning of the program will not be attained until the conclusion of the entire related research effort.The material presented in this report provides a description of a simple dynamical model that can be used for determining the physical interaction of vehicles in a collision scenario. Such a model is of use in...

Development of A Path Flow Estimator for Inferring Steady-State and Time-Dependent Origin-Destination Trip Matrices

Zhang, Michael
Nie, Yu
Shen, Wei
Lee, Ming S.
Jansuwan, Sarawut
Chootinan, Piya
Pravinvongvuth, Surachet
Chen, Anthony
Recker, Will W.
2008

Reliable origin/destination (O-D) data are critical to many applications in transportation planning, design and operations. Because of the high costs of and challenges in obtaining reliable O-D trip matrices from surveys or other direct sampling methods, estimating O-D trip tables from a readily available data source, traffic counts, provides an attractive, economical alternative. This project investigates one such an estimation method and implements it in a user-friendly software tool called Visual PFE TD. The developed O-D estimation tool can be used to obtain both static and dynamic O-D...

The I-880 Field Experiment: Effectiveness Of Incident Detection Using Cellular Phones

Skabardonis, Alexander
Chira-chavala, Ted
Rydzewski, Daniel
1996

This report describes the evaluation of the effectiveness and adequacy of cellular phones for incident detection as an alternative to infrastructure-based surveillance systems. The analysis was part of the I-880 field experiment using the California Highway Patrol's (CHP) Computer Aided Dispatch (CAD) incident database. Cellular phones have the highest detection rate among the examined detection sources. Results from the study, however, indicate that incidents reported by cellular phones show greater incident durations than similar incidents reported by the CHP or the Freeway Service...

Field Operational Test of Tools for Facilitating Smart Travel Choices Through Real-Time Information

Zhou, Kun
Wang, Yanqiao
Li, Jingquan
Wachs, Marty
Walker, Joan
Meng, Huadong
Friedman, Jason
Zhang, Wei-Bin
2018

This report documents an effort to assess whetherintegrated multimodal real-time traveler information can encouragetravelers to consider transit as a more viable choice. Under the sponsorship of the California Department of Transportationand in partnership with the Los Angeles Metropolitan Transportation Authority,California PATH developed and field tested Trip2go --a suite of web-based and mobile-phone-based applications incorporating real-time transit and highway condition information. Both objective and surveys were collected to support statistical and modeling analyses to evaluate the...

Finding and Analyzing True Effect of Non-recurrent Congestion on Mobility and Safety

Varaiya, Pravin
2007

This report summarizes empirical research about the causes and impact of non-recurrent congestion. A method is presented to divide the total congestion delay in a freeway section into six components: the delay caused by incidents, special events, lane closures, and adverse weather; the potential reduction in delay at bottlenecks that ideal ramp metering can achieve; and the remaining delay, due mainly to excess demand. The method can be applied to any site with minimum calibration, but it requires data about traffic volume and speed; the time and location of incidents, special events and...

Improving Mobility through Enhanced Transit Services: Transit Taxi Service for Areas with Low Passenger Demand Density

Li, Yuwei
Miller, Mark
Cassidy, Michael
2009

This research report is the final deliverable for PATH Task Order 6408: “Improving Mobility through Enhanced Transit Services”. The purpose of this task order is to explore alternative methods of providing transit service to areas with low passenger demand density. This report first presents analytical models for determining optimal headway and line spacing for fixed-route, fixed schedule buses, either with fixed stops or allowing buses to stop anywhere along the route. Next, transit taxi services with either fixed or flexible routes that specifically target focused demand patterns are...

Using Cooperative Adaptive Cruise Control (CACC) to Form High-Performance Vehicle Streams

Shladover, Steven E
Nowakowski, Christopher
Lu, Xiao-Yun
Hoogendoorn, Raymond
2014

This research identifies the operational concepts for managing cooperative adaptive cruise control (CACC) vehicle maneuvering and traffic flows. This includes approaches for grouping the CACC vehicles, ranging from ad-hoc to centrally coordinated strategies, and the incentives that could be used to facilitate the vehicle clustering, both operational and financial. These are particularly important at low market penetrations, when the CACC vehicles are likely to be widely separated. The dissolution of CACC strings is also discussed, since this needs to be done carefully to avoid adverse...

Geographical Routing Using Partial Information for Wireless Ad Hoc Networks

Jain, Rahul
Puri, Anuj
Sengupta, Raja
2001

In this paper, we present an algorithm for routing in wireless ad hoc networks using information about geographical location of the nodes. We assume each node knows its geographical position and the position of the node to which it wants to send a packet. Initially, the nodes only know their neighbors but over time they discover other nodes in the network. The routing table at a node S is a list ((pi, Si)) where pi is a geographical position and Si is a neighbor of node 5’. When node S receives a packet for a node D at position pos(D), it finds the pi in its routing table which is closest...

Stated And Reported Diversion To Public Transportation In Response To Congestion: Implications On The Benefits Of Multimodal ATIS

Khattak, Asad
Le Colletter, Emmanuel
1994

The objective of this study is to evaluate the potential benefits of a multimodal Advanced Traveler Information System (ATIS). The propensity of auto commuters to switch to public transportation in response to unexpected traffic congestion is investigated using a detailed survey undertaken in the Golden Gate Bridge corridor in 1993. A stated preference analysis tied to the situation for which the commuting behavior was reported is used to estimate the propensity of travelers to divert to transit under a multimodal ATIS.