Functionality limited in ArcView.
You can generate drive-time areas that use actual street networks and approximated driving times. Equal competition market areas do not adjust for the way people actually travel on the ground. Equal competition market areas are based on "as the crow flies" distances, while people in the real world have to use roads and streets. A two-mile trip might take 5 minutes on one road network and 15 minutes on another.
Pizza delivery provides a good example for the use of drive-time polygons. A company may want to limit deliveries to a total of 15 minutes. This means that the delivery radius of each store would be restricted to a 6-minute drive time (six minutes to the delivery point, three minutes at the delivery site, and six minutes to return, for a total of fifteen minutes).
Overlap can occur. Some store chains have solved this problem by using equal competition areas where drive-time overlap occurs to make each service zone unique and using the drive times at the edge of built-up urban areas to restrict delivery distances and times.
Other examples of drive-time areas include the following:
- Drive time is the defining measure for most urban travel. Potential customers respond much better to a location advertised as being within five minutes than one within two miles.
- Appliance repair operations use drive-time polygons to estimate the total length of service calls.
- Video stores place locations so that at least some minimum population is within five minutes of each store. The threshold population is also dependent on the number and location of competitors within each drive-time polygon.
You can change the speed settings for different road classifications on the Business Analyst Preferences Data tab. You can also create more advanced drive-time polygons with custom road networks, adding barriers and the like with the ArcGIS Network Analyst tools.
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