Operational testing began last November. Eighty buses that primarily run rush-hour express routes from the suburbs to downtown Minneapolis were equipped with tracking devices. The equipment enables bus drivers to communicate with a dispatch center through an onboard computer terminal, allows dispatchers to monitor the progress of buses on computer screens, and provides commuters using a major freeway corridor with up-to-the-minute arrival times on electronic signs, display monitors, "smart" kiosks and - on a limited basis - through videotext terminals in their homes or businesses.
The cornerstone of the $6.5 million public transportation project is a computer-aided dispatch/automatic vehicle location (CAD/AVL) system with GPS. It includes "differential correction" technology that pinpoints bus location well within a city block. The receivers provide current position information to the vehicle's on-board processor, and a location report is transmitted from the bus every 30 seconds to a downtown dispatch center.
At the center, dispatchers monitor the real-time progress of buses on electronic maps displayed on computer screens. The real-time information is then disseminated to the public information kiosks and others.
TESTING THE SYSTEM
When the pilot phase is completed later this year, transportation officials will decide whether or not to widen the coverage area to include all 800 buses operating in the seven counties served by the Metropolitan Council Transit Operations (MCTO).
"The point of the operational test is to gauge how well real-time travel information encourages commuters to consider alternatives to single-occupant car travel, especially public transit," said Marilyn Remer, Travlink project manager. "It is also designed to improve on-time performance and to locate buses in emergencies.
"We have to be creative to increase bus ridership," Remer said. "Our buses have to be more efficient and we have to present travelers with accurate, timely information."
Each bus in the test is equipped with an Intelligent Vehicle Logic Unit (IVLU) that the driver logs onto with an identification number and route code. Immediately after logging on, the driver receives his route assignment with schedule details on the IVLU.
As a bus moves along its scheduled route, its location is displayed at the dispatch center with special icons on digitized maps made by Menlo Park, Calif.-based Etak Inc. Dispatchers track current bus location and status on the display screen through colored bus icons. When a bus is travelling normally, its icon will be shaded green; if ahead of schedule, the icon is blue. If a bus is taking a detour because of road construction or weather problems, the icon is pink.
On the Etak maps, roads are depicted in eight classes, ranging from freeways to alleys. In addition to a comprehensive road network, the mapping software includes railroads, street address ranges, water bodies and political boundaries.
Throughout the scheduled route, the driver and dispatcher receive updated messages of the schedule status automatically. Previously, drivers were required to monitor their own arrival times, calling into the dispatch center for time checks. Because the CAD/AVL system is synchronized to real-time, the driver has an "electronic watch" to help maintain a route schedule.
The system also reduces a phenomenon called "bunching." This occurs when one bus is held up for a few minutes at a stop and the next bus on the same route closes in on the behind-schedule bus.
Bunching often results in empty buses because there is no time for passengers to accumulate at a stop. With Travlink, a dispatcher can identify bunching and make real-time route adjustments such as requesting one bus to overtake another, or to standby.
Commuters at three park-and-ride lots, where hundreds of transit riders often wait in cars for their buses, can view an electronic sign with real-time bus status messages.
Three strategically placed touch-screen kiosks also display the real-time data in conjunction with "static" information, such as bus routes and schedules. The kiosks enable travelers to check their bus status, plan a bus trip and print out a schedule, learn how to join a carpool, and obtain the latest traffic and road information from the Department of Transportation's Traffic Management Center.
Also, several hundred commuter volunteers can access the same real-time and static information on special videotext terminals supplied by U.S. West. Transportation data is downloaded to the terminals through telephone lines, and is intended to encourage commuters to ride a bus when traffic congestion or weather conditions are severe.
DRIVER TO DISPATCH
The bus CAD/AVL system also provides many other features. Beneath the driver's computer screen is a control panel with a number of keys called the Transit Control Head (TCH). Ten keys on the TCH are pre-programmed to send messages from the driver to the dispatch center quickly, without needing to talk on the radio.
One key, for instance, tells a dispatcher the bus is experiencing a mechanical problem. Repair crews can then be sent to the scene.
Also, a silent alarm can be activated to alert MCTO security personnel of an emergency. When a driver activates the alarm, the bus icon on the dispatch display turns red, the map zeroes in on the icon and the system goes to tracking mode automatically. Bus drivers may use this function during incidents such as a drunken or abusive passenger, or a robbery in progress.
"Security is becoming a very acute problem in city buses," said Gary Nyberg, lead supervisor of the MCTO transit control center. "Drivers are very concerned about their safety and want help to get to them as quickly as possible."
CAD DISPATCH SYSTEM
At the dispatch center, the CAD display features pull-down menus and function keys so the average PC user can operate the system. These include a CAD Control Menu to log on and off the workstation and to provide control of the system to the lead dispatcher. The lead dispatcher menu has selections for viewing and modifying dispatcher work assignments, system operational parameters and incident priorities. Other features on the CAD display include a queue management menu that gives the dispatcher the ability to control, display or take action on any incident.
The incident queue lists all open incidents assigned to a dispatcher, sorted by time of occurrence, route/block, operator ID or priority. Emergency alarms and other top priority messages from buses are always listed at the top of the incident queue. A communications control menu allows the dispatcher to define and name call groups for use in data communications and to initiate a data message to a single vehicle, a group of vehicles or the entire bus fleet.
A forms menu allows the viewing, printing or generation of reports from the CAD relational database. The data can be studied by MCTO's scheduling department to improve on-time arrivals and service to passengers.
TIMETABLE IMPROVEMENTS
The actual bus travel information will be compared with "timepoints" or locations where the driver should be at a given time. For instance, if a bus is continually arriving at a timepoint a few minutes early, MCTO officials can make a route adjustment to take up the extra time, or change the schedules to reflect transit realities.
Travlink is a project of Minnesota Guidestar, a partnership between public, private and academic institutions to introduce Intelligent Transportation Systems (ITS) throughout the state. Travlink partners include the Minnesota Department of Transportation, the Federal Highway Administration, Federal Transit Authority, MCTO, Downtown Minneapolis Transportation Management Organization, Westinghouse, Etak, Motorola, 3M, Rennix and U.S. WEST.
Currently, Minnesota Guidestar is involved in 19 projects, including eight of 33 federally funded operational tests and other smaller scale projects. The projects focus on the areas of traffic management, traveler information, rural transportation and commercial vehicle operations.
