Dept. of Transportation
Metro Transit Division

King Street Center
201 S Jackson St
Seattle, WA 98104
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Automated Vehicle Monitoring

Function description: The Smart Bus demonstration AVM functions installed at Central Base included:

Mobile TA Tools: Installed on a pc in the hostler's shack (vehicle maintenance dispatcher's office), this tool allowed VM staff to obtain a snapshot of several coach conditions as the demo coach returned to the base. Normal conditions were displayed on the screen as green, a temporarily out of tolerance condition was displayed as yellow, and a currently out of tolerance condition was displayed as red.

TA Tools: This tool provided VM staff with next day access to detailed AVM coach data via pre-defined web reports.

Custom data queries: Upon request, the Smart Bus demonstration vendor provided detailed printed data reports based on the Smart Bus demonstration data files.

Discreet Input/Output monitors: Sensors were installed at 24 selected points on the demonstration coaches to monitor for changes in equipment status, e.g. "doors open" or "doors closed." The data from the I/O sensors were not displayed on either version of the generic TA Tools.

Objective 1: Technical Approach

"Bug" test:

On January 12, 2002, Vehicle Maintenance staff created a set of out of tolerance conditions on the out of service demonstration coaches to compare the data reported by the demonstration AVM function with actual observed conditions. VM staff also recorded the observed oil temperature, oil pressure, coolant temperature, and voltage, and compared the observed readings with data reported by the TA Tools web reports. Of particular interest was the performance of the discreet input/output (I/O) sensors installed at the request of Vehicle Maintenance staff as part of the demonstration.

To conduct the test, VM staff disabled:

  • The 35 mph switch on coach 2399, which is a monitored fail safe for the articulation dampening system that prevents trailer sway and jack-knifing at speeds over 30 mph;
  • The radiator fan control switch on coach 9024.


  • VM staff reported that the data from the AVM web reports matched the observed values for oil temperature, oil pressure, coolant temperature and voltage. Coach data reports provided by the vendor for the 35 mph switch and fan control accurately reported the disabled switches in an "off" state.

AVM debriefing:

A debriefing session was conducted on February 14, 2002 with Vehicle Maintenance staff involved in the demonstration to summarize Vehicle Maintenance staff experience with the demonstration AVM functions, lessons learned, and suggestions for improvements for system wide implementation. A detailed summary of the debriefing discussion is available in the appendix of this report.

Initial accuracy issues:

According to participants, both Mobile TA Tools and TA Tools displayed some inaccurate data in the first few weeks of the demonstration. These were identified as software data translation errors and were subsequently fixed by the vendor. Once the initial translation errors were fixed, participants considered the AVM data to have good overall accuracy.

Objective 3: Vehicle Maintenance Staff Feedback

Great potential, but user requirements needed:

In general, Vehicle Maintenance staff said they found great potential in the automated vehicle monitoring functions. To be useful to Vehicle Maintenance staff, the type of data collected by the system would need to carefully match staff needs, as well as the way the information is conveyed to VM staff.

Discrete I/O data more valued than J1708:

VM staff considered the demonstration data from discrete input/outputs (I/Os) as more valuable than information from the vehicle's J1708 network, such as oil pressure, which currently can be monitored by gauges or a laptop, and available via the demonstration TA Tools and Mobile TA Tools functions. The desired I/O data generally were available only through the custom data reports, available by special request from the vendor.

Examples of I/O data include: the 30 and 35 mph switches, fan control, rear door, and wheelchair lift cycles. VM staff identified exhaust back pressure and air intake restriction as useful I/O data items for a future AVM system, which would require additional sensors.

TA Tools web reports not user friendly:

The TA Tools next day web reports provided in the demo generally did not meet VM staff needs. Staff noted the user interface was clumsy and required the viewer to go through many screens to view the data they wanted. Participants considered the charts and scales difficult to read.

TA Tools data turnaround time too long:

As implemented in the short term demonstration, detailed AVM data were available in the web reports the day after the coach pulled in to the base. This was not soon enough to really be useful, debriefing participants said. Ideally, detailed diagnostic data would be available in real-time, or at most, an hour after the coach's pull in at the base.

Custom data queries emphasize need for exception reporting:

When participants requested special data queries from the vendor, they were surprised by the volume of data they received, for example, some measures were recorded every second. Upon viewing the reports, participants said they really wanted to see the exceptions or out of tolerance items, for example, all coaches with coolant temperatures above 250 degrees.

Objective 4: Issues and Recommendations for Implementation

Mobile TA Tools improvements:

VM staff noted the primary value of implementing the Mobile TA Tools or similar function would be the ability to triage buses returning to the base according to their need for maintenance. According to staff, the function would also need to indicate which component is out of tolerance, and include information from discrete I/Os.

Location of Mobile TA Tools:

Possible future locations at the base for Mobile TA Tools or similar type of equipment for triaging coaches included the hostler's shack the mechanics office, assuming the equipment is staffed around the clock. Locating the equipment at the fuel building has an advantage, as all coaches are fueled daily, or in a case of trolleys, have their fareboxes pulled.

AVM System Reports:

Based on their experience with the demonstration TA Tools web reports and vendor-provided custom data reports, debriefing participants said a fully implemented AVM system should provide:

  • Data available in real-time or within an hour of coach pull-in.
  • The ability for users to generate reports by selecting desired data elements from a menu;
  • Reporting capabilities for discrete I/Os;
  • Exception reporting;
  • Preset or canned reports, as well as the ability for users to change the canned reports themselves if necessary.

Technical Staff Debriefing:

Participants noted installation of the 24 discrete input outputs (I/Os) on the demonstration coaches took the vendor a considerable amount of time. It is expected that with experience, the process can be streamlined and standardized, but is likely to remain labor-intensive.

Objective 5: Potential Long-Term Benefits

Mobile TA ToolBetter triage would save time and money:

According to debriefing participants, identifying coaches with out of tolerance conditions as they pull into the base would allow more coaches with problems to be parked in the "BO lane" or holding area for coaches with problems, rather than parked with the other coaches. Participants estimated that accessing BO coaches "buried" in the yard occurs at least once per shift at each base, requiring approximately 30 minutes of staff time per incident.

TA Tools (Historical web reports)

Potential benefits of diagnostic data:

Debriefing participants said quick availability of diagnostic information will help reduce the time mechanics spend diagnosing problems. With this information available, Vehicle Maintenance staff expect they will:

  • Manage fleet availability more effectively by identifying which coaches can go back into service and when;
  • Manage staff work flow more effectively by identifying the expected duration of a repair job and staff availability to perform the work;
  • Provide more preventive maintenance by utilizing the time saved from more efficient repairs.

Ability to track fleet performance:

VM staff anticipated the AVM data would be valuable to vehicle maintenance chiefs in identifying performance trends by fleet type over time.

Wheelchair lift preventive maintenance (PM) process:

VM staff said they are interested in examining lift usage, rather than vehicle mileage, as a possible basis for scheduling PM. The potential cost savings could be large if wheelchair lift preventive maintenance could be done more efficiently, as each PM requires approximately eight hours of labor, according to participants.

Updated: Sept. 2002