-------incoming query--------- We have updated the TAZ for our MPO area using Arc/Info and Tiger92 lines. They don't exactly overlay the Tiger98 lines. Would ya'll mind if we just sent you those polygons in Arc export format and skipped the TAZ-UP software process? ----------RESPONSE------ Sorry. You MUST use TIGER/Line 98. CTPP is a CENSUS program, and we are limited to using what the Census Bureau tells us. If you read the reference section (pages 7-8), it tells you the "equivalency file" that the Census Bureau needs--it requires the CENID and POLYID from TIGER/Line 98. You can use ArcInfo, and bring in TIGER/Line 98, and write a lovely AML to do the work for you. If you do this, please let others on the CTPP listserve know. Maybe someone else can benefit ! You DO NOT HAVE TO USE TAZ-UP!!!!