Chapter 11 - Minicase 2

Geographical Information System at Dallas Area Rapid Transit

In preparation for answering the questions, review the Dallas Area Rapid Transit web site.

  1. Describe the role of data in the DART system.

    The data from the DART system provides the input for all kinds of management questions including travel time, route profitability, position of a bus, and much more.

    The data can be used to answer questions such as implications of proposed fare hours of service and route changes.

  2. What are the advantages of computerized maps?

    These maps can be modified easily and at a low cost. The case provides the example of a manual map costing $13,000 vs. the cost of the new computing infrastructure plus 3 feet of plotter paper for a computerized map. This can be a large difference when comparing many old manual maps to new ones.

  3. Comment on the following statement: “Using GIS, users can improve not only the inputting of data but also its use.”

    Data input to a GIS can be editted on input. There is no corresponding check on manual reports or maps.

    As soon as the data is in the GIS, it can be used to produce queries and maps. This imeediate data availability is a huge improvement over the manual approach.

    The GIS can support more sophisticated analytical techniques that are beyond the ability of the manual system. For example, if the GIS has data stored of the travel time between each stop, it can compute total trip time by adding up all the times between the relevant route stops.

  4. Speculate on the type of information provided by the GPS.

    The Geographical Positioning System (GPS) provides the position of a stationary or moving object at any given time, as longitude and latitude values. A GIS system can transform any GPS location into street addresses for use by the public. For example, Bus #202 is now on Constitution Ave. at 14th Street.