Cross-cutting Issues

The Florida Department of Transportation (FDOT) has begun a pilot project to monitor wind
speeds on bridges during severe weather events and provide the information to the public
safety community in real-time. Currently, during severe weather events, law enforcement
personnel are stationed at bridges and use handheld anemometers to measure wind speeds
and help determine when to close bridges. The FDOT intends to assist the public safety
community by providing a safe, cost effective, and accurate alternative for measuring wind
speeds and disseminating the information to stakeholders. The project will use an existing
National Oceanic and Atmospheric Administration satellite-based data collection system to
relay the wind speed threshold alarm information from bridges to an FDOT satellite ground
station. This approach will save money by avoiding recurring telephone or cell phone costs
that would typically be needed to communicate with field devices such as wind speed
monitors. Data dissemination to traffic management centers will be provided by using the
internal FDOT state-wide intelligent transportation system network thus also avoiding the
use of the public telecommunications infrastructure that may be compromised precisely when
needed during a severe weather event such as a hurricane.

Authors: Randy Pierce, Brian Kopp Ph.D.

Presented at the 18th World Congress on ITS, October 2011, Orlando, Florida

Transit Signal Priority (TSP) systems have largely been deployed using localized communications between the vehicle and the intersection for which priority treatment is desired.  This has been accomplished using a wide variety of short range, wireless communications technologies requiring an infrastructure at the intersection and equipment on the vehicles.  Such an infrastructure can be costly and in a City such as New York, with the density of intersections (there are over 12,400 intersections connected to the central system) deployment of TSP is cost prohibitive. 

TransCore ITS

Presented at the 18th World Congress on ITS, October 2011, Orlando, Florida

The primary objective of this paper is to study and analyze the temporal characteristics of
traffic congestions and the associated speed distributions for congested expressways based on
the Floating Car Data (FCD) in Beijing. First, the temporal distributions of congestions with
different intensities are analyzed using the FCD of 5 workdays for a particular expressway
Link N26376. Results show that the longer the continuous congestion lasts, the lower the
speed distribution interval is. Then, the distribution curve is fitted, which finds that the
Log-Logistic model can well describe the survival function distribution of the severe
congestion durations for morning peak-hours of Tuesday. By comparison, it is found that the
duration distribution value of severe congestions at the aggregation interval of 2-minute is
lower than that at the 5-minute interval, and the duration distribution value of severe
congestions on Link N26376 is higher than that on its downstream Links N24162 and N23971.
Finally, the speed distributions in two proposed categories of congestion periods are analyzed
and compared. Results show that if the speed in the present time period falls in a higher
distribution interval, then the probability that the severe congestion will dissipate in the next
time period will be higher.

Authors: Lin Zhu, Lei Yu, Huimin Wen

Presented at the 18th World Congress on ITS, October 2011, Orlando, Florida

Methods to effectively monitor arterial traffic have commanded center stage as new tools and technologies such as vehicle probe data and Bluetooth^TM traffic monitoring have emerged to cost-effectively provide accurate, real-time, continuous, network-wide monitoring of freeway systems.  Within metropolitan areas, the network of high-volume, multi-lane arterials is critical to the daily movement of commuters to jobs and services, to distribute freeway traffic to local streets, and to provide diversion routes during major incidents.  Many of the same technologies that have revolutionized freeway traffic monitoring promise to do the same for signal-controlled arterials.  However, initial demonstrations and implementations reveal a variety of issues, many of which are inherent to the fundamental nature of traffic flow that differentiates arterials from freeways.  The I-95 Corridor Coalition’s Vehicle Probe Project (VPP) has successfully delivered high quality freeway travel time data on a roadway network comprised of over 5,000 centerline miles since its inception in 2008. The project also includes a component consisting of approximately 900 miles of arterials that link the major freeways and provide diversion routes in the event of incidents.  The validation program that monitors data quality for freeways also collects data samples on the arterial network. This paper characterizes the critical challenges in providing quality traffic data on arterials based on data collected as part of the I-95 VPP and through interaction of a committee of transportation professionals that provide guidance to the project.  The findings from the I-95 VPP are germane to any probe-based arterial traffic monitoring system.

University of Maryland

KMJ Consulting, Inc.

I-95 Corridor Coalition

Presented at the 18th World Congress on ITS, October 2011, Orlando, Florida

Microscopic simulation can provide significant support to traffic management center (TMC) operations.  However, traffic simulation applications require data that are expensive and time-consuming to collect.  Data collected by TMCs can be used as a primary source for the provision of the required data.  The goal of this study is to explore the development of methods and tools for the use of microscopic traffic simulation models to support the TMC software implementation, operation, and testing on one hand, and the use of ITS data to support the development and calibration of simulation models on the other. 

The study developments include methods and software utilities that use the existing TMC databases and other available information for the preparation and calibration of microscopic simulation tools.  In addition, the development includes methods and utilities to support testing of the TMC software modules and data archiving processes. The use cases of this study demonstrate the capabilities of the developed simulation environment, which can provide a powerful support for the evaluation of TMC software.  In addition, the environment can provide an effective mechanism for operator training with the TMC software.

Department of Civil and Environmental Engineering

Florida DOT

Presented at the 18th World Congress on ITS, October 2011, Orlando, Florida