1. Geocoding of 2007 WMATA Rail Survey
Travel Forecasting Subcommittee
July 18, 2008
Clara Reschovsky

2. 2007 WMATA Rail Survey Period of study: April 17 - June 22, 2007
Forms distributed to 1 in 3 riders
Response rate – 25%
Completed questionnaires – 66,321
84% home based trips

3. Data Collection 12 Data Items Station receiving card
Origin/Destination purpose
Mode of access/egress
Fare type
Exit Station
Home Jurisdiction
Home address
Home Zipcode
Vehicles available
Federal government employee
Transit benefits

4. Geocoding Process Total records: 66,321
49,743 (69%) had some home geographic information
Data inputs: Structure number, Street name, Zip, Jurisdiction of residence
Used Navteq streets as base map
Half auto-matched
Misspellings, missing Struct. #s, missing Street types

5. Manual Geocoding Hired temporary geocoding clerk
fixed misspellings
used zip codes & Jurisdiction of Residence
use internet mapping services
added missing street types
added missing directionals/quadrants
quality control check for jurisdiction of residence
Matched (or marked out of the region) an additional 21,262 records
used zip codes & Jurisdiction of Residence to narrow search for ambiguous addresses
Matched (or marked out of the region) an additional 21,262 records
- fixed misspellings
- used zip codes & Jurisdiction of Residence
- use internet mapping services
- added missing street types
- added missing directionals/quadrants
- quality control check for jurisdiction of residence

6. Allocation Process
Step 1: Generate allocation file by creating variables for home station and mode of access to home station
Step 2: allocate records with partial addresses
Step 3: fully allocate records without address info
Home Metro Station is created based off of trip purpose. If a respondent is coming from home than the station they board at is their home station and if the respondent is going home, than their destination station is their home station. 84% of riders were either coming from or going to their home.
Access to home station is created by the same process once the home station is determined. Their mode of access or eggress to/from that home station becomes their mode of access to MetroRail.

7. Allocation Process: Step 2
2,367 records with partial address information allocated using a combination of the following variables
Street (entire street name)
Street Name (1st 4 Characters)
Residential Zip
Mode of Access to home station
Home MetroRail Station
Jurisdiction of residence

8. Allocation Process: Step 3
18,527 records contained no geographic residential information
Have to allocate from fewer variables
Mode of Access to home station
Home MetroRail Station
Jurisdiction of Residence

9. Results Prevalence of Metro usage by TAZ
Summarized by home TAZ (includes non home based trips)
Intensity of use
Light blue = about 5 metro rail trip for every 100 persons per day
green= about 19 trip for every for every 100 persons per day
Orange= about 38 trip for every 100 persons per day
Yellow= about 75 trips for every 100 persons per day
Red = 1 or more metrorail trips per day per person

10. Results cont’d
Prevalence of Metro usage by TAZ for area served by MetroRail

11. Results cont’d
Prevalence of Metro usage by TAZ for riders who walk to their home station
Oppurtunities for additional development on orange line to new carrollton