Remote video as traffic cop
Dec 1, 1999 12:00 PM
ACCESS CONTROL & SECURITY SYSTEMS INTEGRATION STAFF
Electronic traffic management and information programs have previously relied on a system of sensors to estimate traffic parameters. The prevalent technology for this purpose in the past has been magnetic loop detectors buried underneath highways to count passing vehicles. Various types of aircraft are also used by radio or television stations to monitor traffic, mostly during rush hour.
Now there is a new world of capabilities for the capture, transmission and storage of video images for use in traffic management. The tools are digital technology combined with advanced image compression techniques. Remote video systems have achieved notable advances as a result of new and improved technologies. Digital cameras and digital storage capabilities in traffic applications make possible enhanced resolution, improved manipulation, faster transmission, reliable storage and convenient retrieval - all of which increase the usefulness of these systems and make them viable for traffic monitoring.
Video monitoring systems provide a number of advantages over old methods of traffic monitoring. A larger set of traffic parameters can be monitored in addition to vehicle counts, types and speeds as well as causes of congestion and recurrent accidents. In addition, traffic can be monitored 24 hours a day, seven days a week. Several transportation departments nationwide are realizing the benefits of the technology.
The collaborative efforts of three companies - Image Sensing Systems, Econolite Control Products and Vision Systems Group - have helped bring 24-hour monitoring of traffic to the fore. Image Sensing Systems Inc. (ISS) emerged in 1984 when a professor at the University of Minnesota had the vision of using video image processing technology for advanced traffic management applications.
The vision became reality when ISS made the technology available in the Autoscope system. ISS, headquartered in St. Paul, Minn., has a strategic alliance with Econolite Control Products, which manufactures the product and is responsible for distribution in North America. Econolite Control Products has been creating traffic management applications since 1933. The company introduced the first digital fixed-time controller (1966), the first digital actuated controller (1968), the first computer-based coordinated traffic control system (1970), the first distributed closed-loop arterial system (1982), and the first multiple-channel commercial video vehicle detection system (1992).
Vision Systems Ltd. is a technology-based manufacturing and services company that markets high-value products, contract engineering and technology-based services worldwide. Its video-based surveillance and security systems are sold under the ADPRO brand name. Vision Systems Group manufactures and distributes ADPRO remote video-based surveillance and security systems in North America. ADPRO Fast Scan provides fast transmission of quality color or black-and-white pictures, plus simultaneous bi-directional audio communication using standard or digital telephone lines. Fast, high-quality pictures previously required expensive transmission equipment along with dedicated special cabling, such as fiber optics.
The ADPRO Fast Scan provides color motion video of traffic using standard PSTN or ISDN phone lines for traffic monitoring, integrated toll, vehicle enforcement and electronic traffic management.
Application: Omaha, Neb. The city of Omaha, Neb. whose population is more than 380,000 with a metro area population of more than 700,000, recently installed the Autoscope/ADPRO system to assist with traffic control. The Autoscope Traffic Alarm Monitor automatically alerts an operator to changing traffic conditions. It provides real-time traffic alarm information through a graphical user interface. The system frees operators from the tedious task of manually scanning CCTV surveillance cameras to detect incidents or other unusual traffic events.
Operation and maintenance of traffic control devices and equipment - especially traffic signals within the city limits as well as in some of the surrounding communities - is handled by the Traffic Engineering Division of the Public Works Department. There are more than 700 traffic signals in Omaha. Motasem Al-Turk, special projects engineer for the Omaha Public Works Department, oversees the traffic monitoring program.
The ADPRO product was proposed as add-on hardware to the vehicle detection camera system in order to meet the city's specifications. These specifications require the ability to transmit video back to the traffic engineering office at a rate of up to 5 frames per second.
The city also required that video be transmitted over standard phone lines as economically as possible. With the installation of video monitoring, live scenes from problem spots often save maintenance crews and engineers long trips to the intersection to check on problems.
Mr. Al-Turk says, "The new system provides us with video quality that is enough for the engineer or technician to understand and analyze traffic problems at the signalized intersections." It transmits analog video from the Autoscope vision machine at the intersection traffic signal controller cabinet via ADPRO Fast Scan to the office PC through a dial-up modem and standard phone line. At the office PC, a digitizer board transforms the analog video to digital for viewing.
Econolite installed the system for the city in the winter of 1998.
Application: Ottawa, Ontario Ottawa, the fourth largest city and the capital of Ontario, has also been using ADPRO products for the past few years to monitor traffic in a region with a population of approximately one million. In 1998, the region of Ottawa-Carleton installed 17 new traffic signals and modified more than 200 others. Currently there are 835 signalized intersections within the Ottawa-Carleton metropolitan area with personnel on-call 24 hours a day, 7 days a week to repair traffic lights and replace signs.
In recent years the Ottawa-Carleton region has been involved in extensive renovation and reconstruction as part of the Restore the Core campaign. This restoration has wreaked havoc with traffic.
John Nicholls, superintendent of signals and data communications, has worked with the region of Ottawa-Carleton for 23 years and played an integral part in the decision to develop a traffic-monitoring center along with Doug Brousseau, director, and Jim Bell, manager of traffic operations. The ADPRO Fast Scan was chosen for a test site in September of 1997 with results that prompted the continuation of camera installations at 15 more sites last year and 10 scheduled for 1999.
Tony Mokohonuk, commercial sales manager for CANGUARD/Protection One, the Ottawa-Carleton project system installers, comments: "The monitoring facility required immediate video transmission to provide status reports of traffic congestion and selected the product based on speed and quality." Pelco Spectra II cameras and ISDN bridges by ADTRAN firmed up the monitoring system with Vision Systems Site Master camera management software.
The region of Ottawa-Carleton maintains some 870 miles of regional roads that link Ottawa-Carleton and operate 850 sets of traffic signals. There are more than 855 signalized intersections in Ottawa-Carleton. The new traffic control center, which is staffed weekdays from 6:30 a.m. until 6 p.m., communicates with more than 725 intersections, via leased telephone lines, communication cable and spread spectrum radio.
The Centralized Traffic Control System is PC-based, hosted on QNX and written in C. This software was designed and implemented entirely by regional staff.
For every traffic signal that is communicating with the Central Computer System, every change in the signal and pedestrian display is logged into a file and can be viewed at a later date. The size of one file for one intersection for one day can vary from 50 KB to 500 KB. On an average day, the Central Computer System issues more than 4,000 commands to change the timing of intersections.
When Nicholls was asked to comment on return on investment for the Ottawa-Carleton traffic monitoring project, he replied: "I don't know how you measure or put a dollar value on road rage, but we are definitely seeing a decline in that area, along with an increase in public confidence."