Title: KY Module 3: Geocoding and GPS
1KY Module 3 Geocoding and GPS
2What is the single hardest information to get
from a travel survey?
- Location, location, location
- What is the address of YOUR grocery store?
- Easiest to report are home and work location.
Even school addresses are often difficult for
respondents to report.
3Difficulties in location reporting
- Interviewer and processing difficulties
- CATI interviewers not familiar with local
landmarks - Multiple matches to GIS basefile (Main Street,
Washington Street).
- Respondent difficulties
- Street suffix (St, Ave, Blvd)
- Directionals (N, S, E, W, NE, SW, etc)
- Difficult street names
- CATI interviewers not familiar with local
landmarks
4Why do we need this geographic detail?
- Attempt to code origins and destinations to
latitude longitude. - Previously code to TAZs, but TAZs keep getting
smaller, as computer technology allows for larger
O/D matrices. - By coding to lat/long, TAZs can be modified in
the future and the data can be summarized for new
TAZ definition. - Want to link detailed geographic info to model,
e.g. slope, sidewalks, distance to bus stop.
5Better location information
- How to make it easier on respondents to provide
location information?
6Can web-response play a role?
- Complete it on their time, not when the phone
rings. - Sample bias, but high income hhlds and young
males are also part of non-respondents, and this
method is useful for reaching these hhlds.
7Geocoding on Internet
- Interactive Yellow Pages look-up
- Who knows the address of their grocery store or
barber shop/beauty salon? - Point and click on a map to identify a location
- Type in an address or intersection and have the
GIS interface locate it on the map
8GPS may be more accurate and complete, by relying
of passive data collection.
- GPS equipment is small and getting less expensive
everyday. - A new Trimble GPS receiver is the size of a
pencil eraser! But, you still need an antenna.
9GPS in Household Travel SurveysStudies in the
U.S.
- 1995 Lexington, KY proof of concept (100
vehicles) - 2001 CalTrans 3 counties in CA
- 2001 SCAG (Ben Pierce)
- 2001 Ohio DOT (Ben Pierce)
- 2002 Smartraq Atlanta
- TYPICALLY 200-500 HOUSEHOLDS, with up to 3
vehicles equipped per hhld.
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11Example from Geostats
- Comparison of self-reported trips (phone
retrieval) to GPS recorded data - Estimated 25-30 of trips are unreported, but
still working to determine impact on VMT, cold
starts, trips by purpose
12Example from Geostats
- GPS generated maps as a recallmechanism.
People may be able to recall what they did a week
ago if provide a map with numbering sequence and
time-stamp. Use of internet to pass Map to the
respondent. - Test in Louisiana, continued work in Australia
(Peter Stopher)
13Other approaches
- Equipping sample of taxis with vehicle navigation
service in Japan - Tracking cell phone users in Germany and in Japan
(Dokomo) - Activity Motivation and re-scheduling Sean
Doherty
14GPS in truck surveys
- Very difficult to get good response rates from
commercial vehicle surveys - One GPS survey in California (CARB and FHWA),
conducted by Battelle - Only fleets were included, not independent
truckers who make up 50 of the CA fleet.
15GPS in truck surveys
- Large fleets may already have GPS for fleet
management, but not likely to share data with
public sector, cuz it is considered proprietary
information.
16GPS for travel speed studies
- Ability to cover large number of miles
- Only need one person per vehicle (old fashion
method with stop watches needed 2 people) - College students, working part-time, very
comfortable with using palm-tops and laptops for
data entry and data uploading.
17Sample of digital video image, georeferenced to
GPS data
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19GPS for travel speed studies
- Travel Speed along links
- Travel speed compared to posted speed
- Travel speed by functional class
- Examine recurring congestion
- Examine queuing length (defined when speed falls
below 5 mph or less for 5 seconds)
20Show 2 .jpg from Steves CD