Dept. of Transportation
Metro Transit Division

King Street Center
201 S Jackson St
Seattle, WA 98104
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Wireless Data On/Off Load System and Data Management Process

Objective 1: Technical Approach

Technical staff debriefing:

Smart Bus Demonstration project staff reported that throughout the demonstration, data was communicated between the bus and base server via a wireless data on/off load system (WDOLS). Data was downloaded daily from the bus to server. A software and data update was transferred from the server to the bus to demonstrate the WDOLS reliability and bi-directional capability.

Objective 4: Issues and recommendations for implementation

Technical staff debriefing:

  • WDOLS will require security measures to prevent hacking of the base servers, KC WAN, or the equipment on the buses.
  • Adequate emergency power supply will be an issue as more systems are installed at the base facilities: security cameras, onboard systems, Smartcard.
  • The number of systems sharing the base file servers will increase the need for server management and coordination.
  • The set up of the stops and route database onboard the bus involved collecting GPS location coordinates for each bus stop and every 50 feet along the bus route. For system wide implementation, the project team is considering options for the system wide process, including collecting the information while buses operate in service, or using the Transit GIS map.
  • The accuracy of transit stop sequence data remains an issue for the project. Various analysts identified some discrepancies in stop data throughout the course of the demonstration. A goal of the Stop Information System project is to increase the consistency and accuracy of stop sequence data.

OBS Data Management

Technical staff debriefing:

A large body of work exists to address the following onboard systems King County Metro data management issues:

  • By what process are data from the onboard database parsed to the various user databases, for example APC, fare collection, etc?
  • How much data will be stored on the bus before it is overwritten?
  • The resulting historical database is potentially very large. Database issues include:
    • Database structure to allow comparison of planned vs. actuals;
    • How much data is stored and for what duration?
    • What data are stored in summary form, such as averages, vs raw data?
    • What are the legal requirements for historical data, such as L&I, safety?
    • How will the data be viewed by users?
  • Implementation of the biweekly scheduling process in onboard systems environment. By what process will schedule versions be controlled and updated onboard?
    • The project team envisions an automated process for implementing current and next service change onboard, including a trigger for when the bus should use the next service change data set.
Updated: Sept. 2002