Matching Tiger Street Spatial Data to digitized lines in County

[Anonymous]

Hey all,

This is a follow up from my last post. I have digitized street center lines
from a county in State Plane but alas there are no labels for these streets!
However there are labels for the tiger data, but the problem there is that
when the Tiger data is projected to State Plane it does not match up at all.
(It is close enough in some places to tell which streets are which.) So my
current method is to have the County Street layer (no labels) over lying the
Tiger Data (has labels) and moving the Tiger data to match the Counties.
This process is very tedious and I wanted to know if anyone might know a
better way to get this job done. Have considered spatial joins ( center
lines are not consistently inaccurate) , looked for a common field between
the two (State Road ID or something and there was none.) Also tried
different projections and datum's. If I do have to reposition the streets
for the entire county's streets any good methodologies for cleaning up
polylines, organizationalwize to keep track of progress etc. Perhaps this is
one of those "Welcome to the wonderful world of GIS projects.:) Any advice
would be much appreciated.

Hamish

[DWalsh]

Hi Hamish,

Yuck! What a mess. Welcome to the world of ridiculously complex GIS data sources!

My first idea would be regarding the TIGER data; perhaps that was in UTM with a NAD 27 or NAD 83 datum, and you got the wrong one when tdoing transformations? Is the change consistent over the map, or is it 10 feet in one place 200 feet in another? If it is sort of consistent then I would guess that you have a datum problem (we have about a 50 metre variation between the two in New Mexico).

Another option is to rubbersheet the two sets of data; here you assume one is correct, and then pick points on the other map; you might pick 36, and then the software stretches , compresses and twists the second set of data to match the first. Let me know if you want more details.

If there is any way that you can get the attributes from the TIGER data into your street centerlines, then that will be the way forward. Having such data attached as attributes makes your maps 10 times more useful. If there is anyway you can manipulate the attributes to have a common field, say by changing the column names, that will be the best way.

Sorry for such vagueness. Feel free to ask for more details.

Cheers,
David Walsh