The model has evolved through a series of revisions and
modifications since 1996. The first road lines were from
TIGER 1980 Line files which were used to create the CASPER
snow plow routing system. The roads were updated and
attributed in 1996 using the INDOT 1996 Road Inventory
Database. This 1996 version was used in the 1997 Statewide
Travel Demand Model. Local roads were added to the model in
1998 as part of the Statewide Interstate Interchange Study,
and all roads were updated using the INDOT 1998 Road
Inventory Database. Nearby roadways in Illinois, Kentucky,
Ohio, and Michigan were added in 1999. More local roads in
Southwestern Indiana were added in 1999 - 2000. Updates and
revisions occur as the model is used. Traffic counts were
obtained from the 1998 Indot Road Inventory Database. Some
were updated by manual counts in 2000. The model was again
updated in 2003-2004, creating version 4 of the Statewide
Travel Demand Model (ISTDM4). Additional county and local
roads were added to the model network. State jurisdictional
roadways were updated using the INDOT 2000 Road Inventory
Database. Traffic count data was updated from the INDOT 2000
Road Inventory Database, as well as other best available sources
(INDOT counts, MPO/RPO counts, and bridge inventory counts).
For more detailed information on the development and use
of the model, contact INDOT through:
(1) Steve Smith, Systems Planning Coordinator, 317-232-5646
(2) Kirk Mangold, Program Developement, 317-233-1061
(3) the "Travel Model User's Guide" (Task 3.3.3.1 Technical
Report) " printed March 2001 as part of the I-69 Evansville
to Indianapolis Study, Tier 1 Environmental Impact
Statement,Vol 1.
(4) the "Travel Model User's Guide" for the Indiana Statewide
Travel Demand Model, version 4 (ISTDM4)