How to Use VISION

1. Each version of the VISION model consists of two workbooks. (We use the VISION 2.0 version as an example in the following, but the instructions apply to all versions.) The two workbooks in the VISION 2.0 version are called"VISION 2.0 Fixed-MPG Base Case with AEO 2003 Data" and "File to be copied for all runs using VISION 2.0 Fixed-MPG Base Case."

2. For each run of the model,

• Open ONLY the "File to be copied…" When opening the file, answer "No" when you are asked whether you would like to update all linked information.
• Immediately save it under a different file name. The new file name should reflect the underlying assumptions of the specific run.
• Do NOT change the VISION 2.0 Fixed-MPG Base Case file.

3. The File to be copied... and the copy you save are linked to the VISION 2.0 Fixed-MPG Base Case file. The links are to the "results" of the Fixed-MPG Base Case. When inputs are made to "Model Input" sheet on the copied file, the results of the run are compared directly to the Fixed-MPG Base Case on that sheet (as well as several other sheets).

4. The "Model Input" sheet allows you to input various assumptions about the future of vehicle technology and vehicle use, such as market penetration of various light- and heavy-vehicle advanced technologies, vehicle energy efficiency, alternative fuel use, VMT, and auto vs. light truck share of total light-duty vehicle sales. All items highlighted in yellow on the sheet can be modified. The assumptions are generally input in 10-year increments: 2000, 2010, 2020, 2030, 2040, and 2050. However, the model is set up to accept other starting dates for vehicle technology and fuel shares.

5. The model calculates energy use, oil use, and carbon emission results for all years between 2000 and 2050 but displays only the results for 2000, 2010, 2020, 2030, 2040, and 2050 on the "Model Results" sheet. If results for intervening years are needed, they can be found in various worksheets.

6. The model calculates average new car and light truck fuel economy for 2000, 2010, 2020, 2030, 2040, and 2050 on the "Light Vehicle MPG" sheet. It does not compute the results for intervening years, though these values for each technology can be found on each technology's individual worksheet.

7. As stated in item 4, assumptions are generally input in 10-year increments, though starting dates may differ from 2000, 2010, 2020, 2030, 2040, and 2050. The model uses linear interpolation to estimate market shares and fuel economy improvements for the years NOT specifically input on the "Model Input" sheet. If you want to input specific vehicle fuel economy or market penetration in specific years not listed on the "Model Input" sheet, you will have to hard-wire those inputs in the model's vehicle technology sheets.

8. You need only input data to the "Model Input" sheet and review the run results in the "Model Results" sheet. However, there are a total of 35 sheets in this model. Most are self-explanatory. One in particular needs to be commented on: "Lt Veh Incremental Cost Summary." The "Model Input" sheet permits you to input vehicle cost ratios for the various light vehicle technologies. These ratios in turn generate the results shown in the "Lt Veh Incremental Cost Summary." However, we have not evaluated the cost ratios in the model and thus have not presented the cost summaries in any of our presentations of the model.