UPDATE Volume 2, Number 3 Articles - Summer Quarter 1998

ORION ARTERIAL TRAFFIC STATUS SYSTEM ­ Bob Sands, Edwards & Kelcey

The Arterial Traffic Status (ATS) system directed at a current "gap" in regional traffic status information, which to date has focused primarily on the area's freeway system. As a key component of the ORION Model Deployment Initiative, this ATS system provides for data collection on 38 selected arterial roadways throughout the Twin Cities metropolitan area. It will also provide display of "real-time" traffic conditions for traveler information and interagency traffic management via the Data Distribution Nodes.

Over 75 percent of the Twin Cities nearly 2,500 traffic signals are part of coordinated, interconnected signal systems. Included are centrally-supervised, computer controlled systems in Minneapolis and St. Paul; and a large number of "closed-loop" signal systems operated by the Minnesota Department of Transportation, St. Paul, Hennepin County, and other metro area counties. Existing traffic detection from these systems -- while used extensively for traffic responsive control within each signal system is not routinely retrieved for real-time regional traffic monitoring. The Arterial Traffic Status Program will fill the void for traveler information with relatively minor legacy system modifications.

The system modifications have five basic components:

1. limited supplemental Autoscope' and loop detector installations and master or local traffic controller change-outs (for system continuity, at selected locations),

2. special detector log "buffer" software for field master controllers in the closed-loop systems,

3. custom "communications servers" at the existing Mn/DOT Metro East, Mn/DOT Metro West, St. Paul and Minneapolis traffic control centers,

4. dedicated, continuous feed phone circuits to supplement existing dial-up connections for retrieval of the Mn/DOT and Hennepin County "closed loop" system data, and

5. operator work stations with custom "journey speed algorithm, database, alarm and status display computational software to process, archive and display the data and to interface through the interagency ORION NET communications systems to share and display regional traffic management and traveler information.

Design and deployment of the system -- a joint effort of Lockheed Martin, Edwards and Kelcey, and the participating agencies is scheduled for completion by December 1998. Current efforts are focusing on "Quickstart" test segments on TH 55 and TH 7 west of Minneapolis, Hennepin CSAH 3, and St. Paul's University Avenue. Econolite Control Products, Advanced Computing Technologies and FORTRAN Traffic Systems Limited are providing development of the special communications servers and detector log buffer software. US West VG 36 bridged analog circuitry was selected for cost effective retrieval of the closed-loop data to the MT/DOT and Hennepin County control centers.

The key component of the status workstation software is a "journey speed" algorithm to account for stopped time and delay due to signals not encountered in freeway applications. This journey speed is based on initial field studies and research by the University of Iowa. The algorithm has been refined by Edwards and Kelcey using extensive Traf-Netsim simulation modeling of various signal system timing and detector location scenarios along with detected spot speed, volume, occupancy parameters. Further refinement and calibration is anticipated following actual systems deployment and using bevel time data from the Automated Vehicle Identification (AVI) travel time calculation component of the ORION Advanced Arterial Management System developed by ADDCO. Workstation displays will provide both colored travel speed indicators by arterial link and tabular data options at several zoom levels as part of the ORION integrated regional display mapping. Operator workstations will also provide special alarms alerting agency traffic management personnel to significant traffic status changes from "normal" or "prior reporting period" conditions and signal system malfunctions.

MOTION IMAGING RECORDING SYSTEM ­ Bob Weinholzer, Project Manager of the MIRS program

Has your vehicle been caught on film, or in digital memory? The extent to which drivers ignore red lights and railroad crossing gates will be monitored in two Minnesota cities by automated cameras that photograph vehicles when those violations occur. The installations will be located in Buffalo and Hermantown (south of Duluth). In addition, a camera will be used to monitor speeding violations in highway work zones at several locations throughout the state. Each installation is part of a continuing test of the Motion Imaging Recording System (MIRS) by the Minnesota Department of Transportation.

In Hermantown, cameras will record red light violations at the intersections of Hwy. 53 and Ugstad Road and at the intersection of Hwy. 2 and Midway Road. At Buffalo, the test involves monitoring a railroad crossing on Hwy. 25 just south of its intersection with Hwy. 55. Two cameras will be rotated among these three sites.

The tests in Greater Minnesota follow testing done in 1996 and 1997 in the Twin Cities metro area. They are the final phase of the testing program conducted by Mn/DOT, the Department of Public Safety, Metro Transit, the Canadian Pacific Railway and the cities of Minneapolis, St. Paul and Bloomington. The tests serve to determine how extensively violations occur and to find out how well the system detects and records violations. The field tests also examine how reliably the technology works in the state's temperature extremes.

The system uses detection devices imbedded in the pavement to trigger a camera when a vehicle enters the intersection after the traffic lights turned to red or when a vehicle is driven around lowered gate arms at a railroad crossing. The system uses a concentrated radar beam to measure vehicle speeds in work zones. The cameras take pictures of the rear of the vehicle, including the license plate. No frontal photos are taken. "When this phase of the testing is complete, Mn/DOT will evaluate the findings and prepare a final report for the Commissioner of Transportation and the other members of the study team. Additional testing is planned for the Twin Cities on I-94 at the north end of downtown Minneapolis in the bus-only lanes and on Hwy. 169 at Pioneer Trail to record real light running violations. A digital camera will be tested this year at the I-94 location. Digital cameras don't require film which means images can be available the same day and could possibly be transmitted by radio.

The cameras will be used for data gathering only because state law prohibits the use of the devices to issue warnings, citations or tickets. However, MT/DOT surveys indicate the public does support using this technology for enforcement. Both the Association of Metropolitan Municipalities and the city of Bloomington are strong proponents of this technology and rank it as one of their top legislative priorities. Fourteen states are already issuing citations using the camera recording system; several others are testing equipment. The technology, that can be used 24 hours a day, frees police to focus on other more serious crimes.

The initial report showed that 12,000 people ran red lights during last year's testing at two intersections and in the metro area 60 percent drove over the posted speed limit in work zones. There is an apparent safety advantage of using this technology, but MT/DOT is not an enforcement agency. The following are some of the reasons cited in favor of the technology:

  • Violations and accidents are reduced,
  • Law enforcement officers are freed to enforce more serious crimes,
  • All violators are ticketed (motorists now are aware that with so many violations occurring that their chances of being caught are minimal),
  • The system operates all the time (not just when law enforcement officers are present),
  • It enhances the safety of law enforcement officers (they do not have to approach motorists who have just violated a law),
  • The system is "color blind" (no possibility of racial bias or age bias),
  • Law enforcement officers cannot be accused of favoritism in the issuance of tickets, and

All types of vehicles are treated the same (law enforcement officers cannot be accused of focusing on motorcycles, sports cars, etc.).

ITS MINNESOTA INDUSTRY FORUM

On 16 September join us at the Sheraton Metrodome Minneapolis from 8 a.m. through 1:30 to hear stimulating presentations about In-Vehicle Initiatives and area ITS Model Deployment Initiatives. The speakers include:

  • August Burgett ­ National Highway Traffic Safety Administration
  • Barry Cantrowicz, Batelle
  • Patrick F. McGowan, Lockheed Martin - Denver
  • Craig Hendrickson, Minnesota Department of Public Safety
  • George Metzler, Daimler Benz-Chrysler
  • William Gardner, Smart Route Systems

Register by September 7th to get reduced rate; phone, fax or e-mail Catherine Ploetz, CTS Events, University of Minnesota- 612/626-2259 Fax626-1632 cploetz@mail.cee.umn.edu

UPDATE STAFF

Article coordination by Lowell Benson of CTS @ Univ. of Minn.
Illustrations by Carol Nagan of BRW
Publication coordination by Deanna Keltner of BRW
Reviews by James McCarthy(FHWA) and Mike Sobolewski (Castle Rock)

UPDATE
Contribute articles for next newsletter by October 14th to itsmail@tc.umn.edu, swhay@tc.umn.edu, dkelt@brwmsp.com or James.Mccarthy@fhwa.dot.gov, thank you.