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CTRE
ISU Research Park
2901 S. Loop Dr.
Suite 3100
Ames, IA 50010
Phone
515-294-8103
Fax
515-294-0467
Webmaster:
mregenol@iastate.edu
Phone Disk
One source of socio-economic data for the model
development is available from commercial phone book packages, for example
the PhoneDisk Powerfinder phone books on CD-ROM. The data sets have the
addresses for all businesses and households in the study area (referenced
by city). In addition, some packages contain the standard industrial code
for the businesses in the city. This is a very important piece of data
for performing the zonal trip generation based on number of businesses
by classification. An examples for the data available from the PhoneDisk
CD-ROM is shown in the next figure.
The following image shows the PhoneDisk CD-ROM
data after being geocoded to the TIGER street map. The point locations
shown in red indicate household locations and the ones in blue depict
businesses. When using the PhoneDisk data for trip generation, being that
there is no specific data on the income or occupancy of the households,
a one purpose model should be used. The household locations will be aggregated
to the zonal level and be factored by trip generation equations (using
a national average of 9.2 trips per household) to determine productions.
The attraction are calculated by aggregating the number of businesses
to the zonal level and equating the zonal attractions to a ratio of the
businesses in the zone relative the entire area multiplied by the total
number of productions.
Important to using the data from the PhoneDisk
CD-ROM is a GIS-based network file with street names and address ranges
to geocode the information. Sources include the TIGER street network (TIGER
1994 or TIGER 1995) and the ArcView StreetMap dataset. Using these tables,
the output from the PhoneDisk selection can be geocoded. The accuracy
of the TIGER street network was tested for select cities and was determined
to provide between 55 and 70 percent of the households and businesses.
This value was improved through the use of the ArcView Street Map data
set. This network provided accuracy in the rage of 65 to 80 percent.
The user should either go back to the Data Elements page or to the Site
Map to continue.
