Cross-cutting Issues

A new, proprietary wireless communications technology has been developed, and is being test- deployed in several cities around the U.S. This Mesh Enabled Architecture (MEATM) developed and marketed by MeshNetworks, Inc., is now being considered for traffic signal system communication linkage in Los Angeles County, California. This paper presents the results of a high-level review of the technology, and its applicability to the traffic signal system, conducted for the information and decision-making of that client. MEATM uses a multipoint–to–multipoint architecture, operates using Direct Spread Spectrum Sequence (DSSS) radio technology in the unlicensed 2.4 GHz band, and (uniquely) provides for every user connected to the system to also act as wireless router units as a “background” process. With more users on the network, the communication system dynamically routes data packets through different user-to-user-to-router-to- user... hops, before ‘landing’ at one of the network’s wire-line connected access points. The MEATM network utilizes the Internet as an integral element, as all data destined for a remote server (or system, or website, or whatever), will pass from the wireless spread spectrum network onto the Internet. The MEATM network does appear to be a viable communication solution for a traffic signal system. In fact, the dispersed and relatively uniform spacings of signalized intersections would provide a significant number of fixed points on the network (with each one also acting as a router for other users’ messages), and thus would appear to be an ideal “anchor tenant” for such a network deployment. The system’s inherent-by-design ability to add more users without degrading throughput performance also makes it an attractive choice. As of the summer of 2003, this communications technology has not yet been deployed for traffic signal system communication purposes; there will be a learning curve for whatever signal system owner elects to be the first to so deploy it.

Glenn Grayson, P.E.

Meyer, Mohaddes Associates

Presented at the ITS America Annual Conference and Exposition, April 26 - 28, 2004 San Antonio, Texas

In order to help improve compliance to specifications and the overall quality of deployed Dynamic Message Sign (DMS) systems within Florida, an ongoing manufacturer qualification program was developed and implemented by the Florida Department of Transportation (FDOT) Traffic Operations Office’s Traffic Engineering Research Lab (TERL). As a part of this qualification program, an NTCIP testing program was developed in order to ensure that manufacturers bidding on jobs within Florida had a suitable understanding of the NTCIP and to ensure that a suitable degree of interchangeability was achieved between systems within the state. Such a program is of particular importance in decentralized agencies such as the FDOT, as it provides a means for forcing interchangeability between the separate FDOT districts within the state. An overview of the motivation, development, and implementation of the DMS NTCIP testing program is presented, along with the general results of the program. Additionally, the conclusion includes a discussion of future related work planned for other types of devices, as well as the effect of recent developments from the NTCIP community on the planned efforts.

Department of Electrical and Computer Engineering - FAMU-FSU College of Engineering

State Traffic Operations Office - Florida Department of Transportation

Presented at the ITS America Annual Conference and Exposition, April 26 - 28, 2004 San Antonio, Texas

The increasing availability of wireless communications has presented agencies
with a potentially more cost effective means of communicating with intersection
controllers versus the use of standard wired techniques.  Inherent latencies and business
models for deployment of wireless communications require that the communications with
intersection controllers be managed in a manner different from the techniques used for
connection to the controllers over standard wired techniques.  An analysis of the amount
of actual useful data typically transmitted vs. the total amount of data transmitted reveals
that for a typical system, where once-per-second status monitoring is desired,
approximately 92% of the transmissions result in no new data about the intersection, or
expressed differently, only 8% of the transmissions are being used for useful data (which
also includes significant overhead).   This is very inefficient use of the available
bandwidth and becomes even more critical where the bandwidth must be shared or has a
cost associated with the number of bytes transmitted/received.  This paper describes an
approach that utilizes the trap capabilities defined in NTCIP 1103 along with some
extensions to the trap mechanism;  the extensions to the standard proposed allow the
agency to control the amount of data sent over the wireless networks on an intersection-by-intersection basis while still meeting their varying needs for real-time monitoring and
control.  These extensions also support such enhanced concepts as backup control centers
and peer-to-peer communications.
Note: the specific details described in this paper may change over the intervening
time between submission and final system deployment as the standards working group(s)
adapt the standard to meet the needs of a wireless media.  Such changes will not alter the
functionality described herein – only the specific data elements used to manage that
functionality.

TransCore ITS, Inc

Presented at the ITS America Annual Conference and Exposition, April 26 - 28, 2004 San Antonio, Texas

In Kansas City, the Missouri Department of Transportation (MoDOT) and Kansas Department of
Transportation (KDOT) have joined together to implement one of the largest and most advanced transportation management systems in the country as part of their Intelligent Transportation System (ITS) deployment programs.  This system utilizes an extensive network of traffic operations system field elements including Closed Circuit Television (CCTV) cameras, Dynamic Message Signs (DMS), Highway Advisory Radio (HAR), and Vehicle Detector Stations (VDS) as part of a system that will help maximize roadway capacity, reduce air pollution and provide a safer travelling medium for the general public.  As is the case with any large Advanced Transportation Management System (ATMS), the communications system is one of the major components, if not the major component, of the traffic management system in terms of both functionality and cost.   
MoDOT and KDOT have designed a unique communications system in conjunction with efforts
from National Engineering Technology Corporation (NET) and Black & Veatch.  The designed
network makes use of sophisticated fiber optic gigabit Ethernet and IP-addressable controller
technologies to provide an environment that is much easier to integrate, maintain and operate,
key issues that face all large transportation management systems.  Through the deployment of
this innovative communications design and newly developed centralized ATMS software, the
DOTs have been able to implement center-to-field NTCIP compliance to a degree not seen in
most of the metropolitan systems already deployed.  This design facilitates simplified system
integration and enables portability and interoperability for further system migrations.
This paper will describe the communications system that supports the KC Scout ATMS.

NET Corporation

Missouri Department of Transportation

Kansas City Scout

Presented at the ITS America Annual Conference and Exposition, April 26 - 28, 2004 San Antonio, Texas

One of the advanced features available in the microscopic simulation programs is an application programming interface (API), which allows users to implement their own control logics within the simulation program. This is especially useful in case the microscopic simulation program does not support certain control functions. However, it is believed that the development of a new API is not a trivial task especially for practitioners. This paper presents the development of an API for coordinated actuated signal control logic for the PARAMICS microscopic simulation program. The developed API for the coordinated actuated signal control allows phase skip, gap-out and force-off, which were generally not well supported by the existing logics and/or functions in the PARAMICS program.

Department of Civil Engineering, University of Virginia

Ajou University

Presented at the ITS America Annual Conference and Exposition, April 26 - 28, 2004 San Antonio, Texas