Sunday, January 13, 2013


This was promised with the BDS system that is now in place that Trimet calls obsolete. It was supposed to do the exact same thing that the new BDS system is doing. The original system was $6 million dollars, this new system costs $34 million dollars (financed with bonds of course). The new system has been a complete failure as of this date. Trimet is one and a half years behind schedule getting it going. Everything that is outlined in yellow is something that was promised that was not delivered.

Automatic Vehicle Locator

Tri-Met will utilize the Dept. of Defense's Global Positioning System of 24 satellites 11,000 miles out in space to improve transit service for its customers.

Tri-Met is now installing a computerized bus dispatch system (BDS) and automatic vehicle locator (AVL) that will improve communications with operators, dispatchers, and customers.

A key advantage of this system is that it will provide information on schedules and performance, and allow schedules and service to be adjusted to improve service reliability.

The AVL also informs dispatchers the location of any of Tri-Met's 770 buses within 10 meters.

This information will help Tri-Met improve operations during snow and ice storms, as well as respond more quickly to an emergency.

The Bus Dispatch System (BDS) is a combination of dispatch equipment and an onboard computer that improves communications between bus operators, dispatchers, garage personnel, and customer service representatives.

The system will display a prioritized list of messages received from bus operators, allowing dispatchers to prioritize and respond to the most pressing operator needs.

Dispatchers can send one digital message to numerous buses throughout the day and evening without using voice communication. For example, all buses traveling over the Hawthorne Bridge could get a route change that relates to service on the bridge. If there is a detour onto a different bridge, the operator can call up the route change and follow those directions. Operators no longer have to write down the detour information or pass it along to operators on different shifts. Voice communication is time consuming and causes poor response time.

The system will automatically send detour information and late arrival information to Customer Service. Tri-Met personnel can relay information to customers about service changes and delays.

The On-Board Computer uses a data card system to provide and record vast amounts of operational information on every trip made in the system, including:

system speed
bus stops
passenger loads
on-time performance (early/late)
off-route operation.

The computer continually tells the bus operator if the bus is on schedule to provide the best customer service. This information will be used by departments such as Scheduling/Planning to adjust and modify schedules.

On specially equipped buses, the on-board computer also will automatically change signage at the end of routes, automatically announce stops and transfer points, and automatically count passengers.

The Automatic Vehicle Location (AVL) System is based on all buses receiving signals from three-to-five satellites and determining their position by triangulation. The buses periodically report their position to the dispatch system which displays it on a 21" computer screen at each dispatch console. Buses can be located within a few blocks when moving, or within 10 meters or less when stationary. This information is updated as often as every as every 30 seconds. This will speed response time to an emergency.

Routes, transfer points, and bus stops can be shown on a dispatcher's display screen. This will be an efficient method of sequencing and spacing service in emergencies (snow and ice) and in regular service where breakdowns, schedule delays, etc., cause buses to become "bunched" along a line.

Baseline Cost is $5.5 to $6 million, with 80% of the cost funded through federal grants. Tri-Met has been working on this project for three years. Full implementation will be complete in early 1997.

Computerized Bus Dispatch

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