January 12, 1995

Mr. Robert Shull, President
TMODEL Corporation
P.O. 1850
Vashon, WA 98070

Dear Robert,

Thank you for fulfilling our request to develop a TMODEL2 emission calculation module. We faced the task of calculating regional emissions for Spokane s Carbon Monoxide Non-attainment area. This calculation was critical for our Transportation Improvement Program.

We knew our model contained two out of three key components for regional emission calculation_vehicle miles traveled (VMT) and operating speed by link. With this information, we needed an additional module to allow the input of emission factors and a few minor calculations.

Your emissions module has worked wonderfully. It saved countless hours of staff time and made our regional transportation model even more effective. With the increasing emphasis on air quality, particularly in Spokane, the module will be very useful. We have already used it to demonstrate conformity of our Transportation Improvement Program and our Regional Transportation Plan. In the future, the module may be used to aid in site-impact analysis.

Once again, you and your staff have responded quickly and professionally to our modeling needs. Your support of the TMODEL2 program is much appreciated. Thank you again for your help.

Sincerely,

Michelle McFarland
Transportation Air Quality Planner