making efficient map layers

[Mark Dieterich]

Steve,

I'm really impressed with the maps on the imaptools site, hope you don't
mind a few prodding questions from a mapserver newbie...

- Does your site actually use some form of generalized layer when zoomed
out?  If so, can you tell me at what point you switch from generalized
maps to shapefiles, it seems really seemless.

- How do you go about changing the width of the different types of
roads?  I assume each class of road is in a different layer and you
somehow manipulate the line width?

- Is there any speed reason to split types of roads, based on the CFCC
type, into different shapefiles or is it just as good to use shp2tile
and then a tileindex?  On a side not, is it possible to throw a wildcard
at ogr2ogr, where by you can specify something likek ogr2ogr dst.shp
src.shp -where CFCC=A1*?  I couldn't figure out if it could take
wildcards or not.  I suppose you could go through and run it for each
A1* type and append it to the shapefile, but this could be a long process.

I'm working on familiarizing myself with the National Map offerings and
will probably have some more questions for you.

Thanks!

Mark