This software was developed for analysis by U.S. Department of Transportation staff of potential fuel economy requirements.
This software uses input files containing detailed information regarding vehicles manufactured for sale in the United States and creates output files containing similarly detailed information regarding such vehicles. If input files containing information in any way (e.g., based on entitlement under 5 U.S.C. 552 to confidential treatment) protected from disclosure to the public are used, some output files created by this software must also be protected from disclosure to the public.
The CAFE Model software is a U.S. government work not subject to copyright pursuant to 17 U.S.C. 105; however, some of the third-party works used by the software are subject to usage agreements, as described below.
The button controls in the application file menus, context menus, and toolbars of the CAFE Model software use images from the Glaze Icon Set (version 0.4.6, released on 3/06/2006) obtained from www.notmart.org. All icons and/or images within the Glaze Icon Set are distributed under the GNU Lesser General Public License (LGPL), version 2.1. The version 2.1 of the GNU LGPL may be obtained from www.gnu.org/licenses/old-licenses/lgpl-2.1.html. A copy of the GNU LGPL is also included as part of the CAFE Model software and may be accessed from the application “Notice Screen” or by browsing the “License” folder in the CAFE Model source code.
The CAFE Model software uses compiled code from the ExcelDataReader library (version 3.7) for reading and processing of Microsoft Excel files. The ExcelDataReader library is distributed under The MIT License. A copy of The MIT License applicable to the ExcelDataReader library is included with the CAFE Model software and may be accessed from the application “Notice Screen” or by browsing the “License” folder in the CAFE Model source code.
If users of the CAFE Model software have any questions about this notice, please contact the current administrators of the CAFE project.
Installation and System Requirements
The CAFE Model runs on IBM-compatible computers using the Microsoft Windows operating system. Although the software does not have strict hardware requirements, beyond what is needed to run the operating system, a dual core Intel compatible processor, with at least 8 GB of physical memory (RAM) is strongly recommended. The software has been developed and tested on computers using Windows 10/11 and Windows Server 2019 but may operate properly on machines using other versions of Windows, as long as a compatible Microsoft .NET Framework is installed.
The CAFE Model was developed using the Microsoft .NET Framework, version 4.8. If the Framework is not already present, it must be installed. Instructions for downloading and installing the .NET framework are available on the Internet at: https://dotnet.microsoft.com/download/dotnet-framework/net48.
Based on the characteristics of machines used in the development of this software, the following table provides a summary of system requirements:
Table 1. CAFE Model System Requirements
|
Dual Core Intel compatible processor (64-bit Quad Core processor recommended) |
|
8 GB RAM (16 GB recommended) |
|
25 MB hard drive space for installation (additional disk space will be required during runtime)[1] |
|
Microsoft Windows 10/11 |
|
Microsoft .NET Framework 4.8 |
Once the system requirements have been met, the latest version of the CAFE Model may be obtained by contacting NHTSA or Volpe Center staff.
The current version of the software is packaged as a stand-alone executable and does not require installation. To operate the model, place the “CAFE Model.exe” file on the desktop and execute it.[2]
CAFE Model Graphical User Interface
The CAFE Model graphical user interface provides users with a set of tools necessary to set up and run multiple modeling test scenarios, which are commonly referred to as CAFE Model sessions. Each CAFE Model session can be configured independently, each with its own set of model inputs and settings. Once configured, the session may be saved for future runs, or executed immediately.[3] When the model runs, the system displays the progress of the compliance modeling process in the main model window.
The model GUI consists of two primary screens: the main CAFE Model window and the Modeling Settings window. The CAFE Model window is used for managing the modeling sessions, while the Modeling Settings window is used to configure them.
To run the modeling system, click on the CAFE Model executable file located on the desktop. When the application launches, a Warnings dialog box is displayed (Figure 1). The user must read and understand the warnings listed prior to using the modeling system.
Figure 1. Warnings Dialog Box
After clicking the OK button in the Warnings dialog box, a Splash Screen window appears (Figure 2), prompting the user to wait for model resources to load.
Figure 2. CAFE Model Splash Screen
Once the model resources are completely loaded, the main CAFE Model window, described below, opens.
The main CAFE Model window (Figure 3) is used to create, configure, and manage CAFE modeling sessions. The main window also controls the model operation, allowing users to start and stop modeling simulation.
Figure 3. CAFE Model Window
When the model first starts up, most of the menu items and toolbar icons are disabled, until a new session is created, or an existing one is opened.
All of the options required for operation of the model GUI may be accessed using a file menu (Figure 4), with most commonly used shortcuts also available on the model toolbar (Figure 5). For user convenience, most of the menu entries may also be controlled using keyboard shortcuts.
Figure 4. CAFE Model File Menu
Figure 5. CAFE Model Toolbar
Some of the most commonly used file menus are listed in the following.
· File > New Session: Creates a new CAFE Model Session and displays the Modeling Settings window to the user.
· File > Open Session: Opens an existing CAFE Model Session.
· File > Close Session: Closes the currently open CAFE Model Session.
· File > Save Session: Saves the open CAFE Model Session.
· File > Start Modeling: Begins CAFE simulation modeling for the currently open CAFE Model Session.
· File > Stop Modeling: Suspends CAFE simulation modeling.
· File > Exit: Exits the CAFE Model. If a CAFE Model Session is still open, it will be closed prior to exiting the model.
· View > Modeling Settings: Displays the Modeling Settings window, where all modeling options and settings may be configured.
· View > Output Location: Opens a Windows Explorer window and browses to the location where the output files and reports of the current session are written to.
· View > Argonne Simulation Results: Extracts the vehicle simulation results, produced at Argonne National Laboratory using the Autonomie model, that are built into the CAFE Model to a user-specified directory.
Users are encouraged to explore all of the additional file menus available within the model. For analysis involving many model runs, workflow can be accelerated and configuration errors reduced considerably by saving a session, reopening it, making desired modifications (e.g., selecting a different version of an input file, or changing a run-time option), and saving (before running) the modified session under a new name.
The description for the menus listed above, as well as all other menu and toolbar items are also displayed within the model GUI’s status bar when the user points to that item with a mouse.
The Modeling Settings window contains several panels for configuring all the runtime options available to the model. The user can operate this window to set up a new session, or modify an existing one, before starting the modeling process. Each of the available configuration panels is outlined in the sections below.
General Compliance Settings Panel
The General Compliance Settings panel (Figure 6) is used to specify what type of modeling the user would like to run. Each model is tailored to different type of analysis, using its own set of assumptions and configuration settings. At present, only one model type is available.
· Standard Compliance Model: The Standard Compliance Model is the default mode of operation for the CAFE modeling system. This model type is used to evaluate technology costs and benefits in response to the required CAFE standards defined in the modeling scenarios.
Figure 6. General Compliance Settings Panel
The notes and keywords inputs are optional and may be specified by the user for diagnostic or information purposes. These are reflected in the summary log file produced by the system and do not affect the actual modeling process.
At present, as shown in Figure 6 above, the current version of the modeling system only supports the Standard Compliance Model. Future development may reintroduce additional types of analysis, such as Monte-Carlo simulation.
On the I/O Settings panel (Figure 7), the user can select the input data files for use with the modeling system as well as the location where modeling results will be saved. In addition, the I/O Setting panel also allows users to optionally compress model outputs into a single zip file at the end of the analysis.
Figure 7. I/O Settings Panel (1)
Input and output locations may be entered by typing the paths into the appropriate textboxes, browsing for a specific file or folder path, or dragging-and-dropping an input file or an output folder directly onto the I/O Settings panel. Two or more input files may be selected and dragged-and-dropped onto the panel simultaneously. In this case, the modeling system attempts to automatically determine if the correct files were chosen based on the names of individual files and populating the required inputs accordingly. After selecting all input files, the user may click on the Save button to load the contents into memory. If an incorrect file is selected for a particular input (e.g., “technologies.xlsx” instead of “market-data.xlsx”), or if the modeling system is unable to load the contents of the chosen input file for some reason, an error message will be displayed to the user as shown in Figure 8.
Figure 8. I/O Settings Panel (2)
The Runtime Settings panel (Figure 9) provides additional modeling options to further customize the model behavior, beyond what is available in the input files. For convenience, several setting “profiles” are defined in the GUI, allowing users to quickly select default options based on a specific type of run.
· Light-Duty: Selects default runtime settings applicable to light-duty analysis for determining new fuel economy standards.
· Light-Duty (EIS): Selects default runtime settings applicable to light-duty analysis for determining a manufacturers’ response to new fuel economy standards.
· Custom: The “custom” option is not selectable by the user. This option is automatically chosen when any of the runtime settings are changed independently.
Along with the predefined profiles, a user may individually configure various runtime settings. The following describes the options that may be toggled from the model’s GUI by the user.
· Compliance Program to Enforce: Specifies the compliance program the model should enforce when evaluating a manufacturer’s compliance state. If CAFE option is selected, the model will seek compliance with NHTSA’s CAFE standards. If CO-2 option is selected, the system will seek compliance with EPA’s CO2 standards. If Both option is selected, the modeling system will seek compliance with NHTSA’s CAFE and EPA’s CO2 standards simultaneously.
· Begin alternative scenario analysis in: Specifies the first model year the system will evaluate for compliance for alternative (non-baseline) scenarios. Any fleet improvements made during analysis of the baseline scenario will be inherited during evaluation of alternative scenarios for each model year prior to the “alternative” starting year.
· Begin technology application starting in: Specifies the starting model year when the system will begin evaluating technologies for application on vehicles. Prior to this year, the system will only determine manufacturers’ compliance levels, generate available credits and fines owed, and use expiring credits (if credit trading option is enabled) to offset compliance shortfalls as needed. Any non-expiring banked credits available prior to start of the analysis (which are specified as input for each manufacturer) will not be used for model years prior to this starting year.
· Evaluate compliance modeling until: Specifies the last model year the system will evaluate for compliance.
· Allow Credit Trading: Specifies whether the model should allow manufacturers to transfer credits between passenger car and light truck fleets and to carry credits forward from previous model years into the analysis year. (The model currently does not simulate either credit “carry-back” or trading between different manufacturers.)
· Cap AC/Off-Cycle Costs: Specifies whether the costs associated with air conditioning and off-cycle credit should be prevented from falling below zero.
· Restrict labor analysis to innovative technologies: Specifies whether the modeling system should consider only innovative technologies during labor analysis calculations. If this setting is false, all technology costs will be considered.
· Exclude BEV/FCV from analysis: Specifies whether the model should remove all BEVs and FCVs from the industry fleet prior to start of analysis and disallow application of new BEVs or FCVs during modeling (including for the ZEV mandate).
· Assumed Payback Miles: Specifies the assumed number of miles during which an added investment in fuel improving technology is expected to pay back. This value is used for the Sales Response model, the Dynamic Scrappage model, and for the calculation of the foregone consumer sales surplus.
· Scale Consumer Benefits: Specifies whether the model should scale the private consumer benefits by a specific percentage during the effects calculations. Valid values are 0 to 100.
· Calculate Implicit Opportunity Cost: Specifies whether the model should calculate implicit opportunity costs during effects calculations.
· Calculate Commercial Operator Opportunity Cost: Specifies whether the model the model should calculate commercial operator implicit opportunity costs during effects calculations.
· Commercial share of ownership: Specifies the percentage of consumers that purchase a light-duty vehicle for commercial use. This option is not applicable if both of the preceding options for calculating the implicit and the commercial operator opportunity cost are disabled.
· Use domestic-only upstream rates for all emission calcs: Specifies whether the modeling system should use the domestic-only upstream emission rate inputs when calculating the vehicular upstream emissions, emission health impacts, emission damage costs, and total emission quantities. If this setting is false, the global upstream emission rates will be used instead.
· Fatality Rate Estimates: Specifies whether to use the low, average, or high fatality rate estimates from the parameters input file. By default, average fatality rate estimates are used.
· Enable Dynamic Economic Modeling: Specifies whether the various Dynamic Economic models available within the system should be enabled for analysis. This includes the Dynamic Fleet Share and Sales Response (DFS/SR) model, the Dynamic Scrappage model, and the Dynamic VMT model.
· Select Sales Estimator to use: Specifies the sales estimator to use for projecting the total vehicle sales in each future model year. When the Fixed Forecast option is selected, the CAFE Model will project a constant light-duty sales forecast into each future model year, based on the initial sales volumes obtained from the product plan industry data (i.e., the sales volumes from the market-data input file); when the User Defined Forecast option is chosen, the model will rely on a user-supplied annual forecast of new vehicle sales; and when the Nominal Forecast option is selected, the system will estimate new sales using an integrated macroeconomic model; and. All options are applicable to the baseline and the action alternative scenarios, and are discussed in greater detail in Chapter Two, Section S5.7.1 of the CAFE Model Documentation.
o Use Price Elasticity estimator for alternative scenarios: Specifies a sales estimator that forecasts the total vehicle sales in each future model year in the action alternatives, based on the price elasticity effect with regard to the incremental differences of regulatory costs, tax credits, and fuel savings occurring between the baseline and the action alternative scenarios. Note that for the baseline scenario, a sales estimator selected from one of the options described above will be used as a reference to forecast the new vehicle sales. This option is discussed in greater detail in Chapter Two, Section S5.7.3 of the CAFE Model Documentation.
o Price elasticity multiplier: Specifies the price elasticity multiplier to use with the Price Elasticity estimator option.
· Select DFS Model to use: Specifies the fleet-share model to use for estimating the fleet shares in each future model year. When the Fixed Fleet Shares option is selected, the CAFE Model will project constant fleet shares into each future model year, based on the initial fleet shares obtained from the product plan industry data; when the User Defined Shares option is selected, the system will rely on a user-supplied annual forecast of light-duty car shares; and when the Experimental option is chosen, the model will use a new macroeconomic DFS model that forecasts the fleet shares in each future model year in response to the differences in fuel economy, vehicle power, and curb weight occurring between the light-duty car and light-duty truck fleets . All these options are applicable to the baseline and the action alternative scenarios, and are discussed in greater detail in Chapter Two, Section S5.7.2 of the CAFE Model Documentation.
o Use Price Elasticity model for alternative scenarios: Specifies a DFS model that forecasts the fleet shares in each future model year in the action alternatives, based on the price elasticity effect with regard to the incremental differences of regulatory costs, tax credits, and fuel savings occurring between the baseline and the action alternative scenarios, additionally taken as the differences between the light-duty car and light-duty truck fleets. Note that for the baseline scenario, a DFS model selected from one of the options described above will be used as a reference to forecast the fleet shares. This option is discussed in greater detail in Chapter Two, Section S5.7.4 of the CAFE Model Documentation.
o Price coefficient: Specifies the price elasticity coefficient to use with the Price Elasticity DFS model option.
· Number of Iterations for Sales Model: Specifies the number of iterations to examine in the convergence loop of the DFS/SR model.
· Disable Dynamic VMT model: Specifies whether the Dynamic VMT model should be disabled during analysis. Warning: This option is intended for internal benchmarking of the annual VMT projections and is not recommended for general use.
Figure 9. Runtime Settings Panel
When a new session is created, or an existing one opened, the main CAFE Model window changes to present the user with several charts detailing the progress of the compliance modeling process. This is referred to as the modeling system’s Session View (Figure 10).
Figure 10. CAFE Model Session View
The top-left corner of the model’s Session View shows the progress of compliance modeling, displaying the current scenario, iteration, model year, and manufacturer being evaluated (Figure 11). In addition, this portion highlights the “in-progress” compliance state of the manufacturer being examined during the current analysis year. The manufacturer’s standard (or required CAFE value), CAFE (or achieved CAFE value), and shortfall (the difference between the required and achieved CAFE values) are displayed along the top axis, labeled “mpg.” The fines owed, accumulated technology costs, fuel savings, and CO2 savings attributable to the manufacturer are displayed along the bottom axis, labeled “$ (m).” As the model progresses, these values change as more technologies are applied to a manufacturer or the model switches to a different manufacturer, model year, iteration, or scenario.[4]
Figure 11. Session View - Modeling Progress
The center-left section of the model’s Session View shows the Vehicle Scatter Plot, with initial and final fuel economy levels displayed for the scenario, iteration, model year, and either the entire industry or the selected manufacturer being evaluated (Figure 12). The category axis displays the range of footprints that represent all modeled vehicles, while the values axis shows the mpg level achieved by those vehicles. The user may interact with the Vehicle Scatter Plot, which is discussed in the following section, to filter the chart’s view between each analyzed manufacturer and the entire industry.
Figure 12. Session View - Vehicle Scatter Plot
The bottom-left corner of the model’s Session View shows the “by-manufacturer” Compliance Performance Chart for the scenario and iteration being analyzed (Figure 13). The user may interact with this chart to filter the view between the model year currently being processed and any other model year evaluated during the study period (past or future). For model years that have not been processed yet, however, the data presented will be based on the last year examined. The category axis displays the manufacturers evaluated as part of the analysis. The CAFE Rating and CAFE (2-cycle) are displayed along the left values axis, labeled “mpg,” while average fuel cost and emission damage are displaying along the right values axis, labeled “$.” The Compliance Performance Chart also displays the average CAFE rating for the entire industry, as a relative benchmark measure for each manufacturer.
Figure 13. Session View - Compliance Performance Chart
The right side of the model’s Session View shows the “by-model-year” Compliance Summary Chart for the scenario and iteration being analyzed. As with the Vehicle Scatter Plot, the user may filter the view between each manufacturer and the entire industry. The category axis, labeled “Model Year,” displays the range of model years evaluated as part of the analysis. The standard, CAFE, and shortfall values attained for each model year are displayed along the left values axis, labeled “mpg,” while fines owed, accumulated technology costs, fuel savings, and CO2 savings are displayed along the right values axis, labeled “$ (m).” When modeling begins, most of the values along the Model Year axis will be empty. As the system progresses through each year, additional information will be presented.
Figure 14. Session View - Compliance Summary Chart
Interacting with the Session View
Each of the available charts in the Session View may be interacted with to change the appearance of information presented to the user. For example, as mentioned above, the user may filter the Vehicle Scatter Plot to display fuel economy information for a specific manufacturer or for the entire industry. In addition, the user may filter the chart’s view to display data for a specific regulatory class or for the combined fleet. When filtering by regulatory classes, if a particular class is not available within the selected manufacturer or industry, it will be omitted during filtering.
Filtering is initiated by pressing on the chart’s area with the left mouse button, then dragging the mouse left or right (to filter between regulatory classes), or up or down (to filter between manufacturers for the Compliance Summary and Vehicle Scatter Plot, or to filter between model years for the Compliance Performance Chart). As the mouse is dragged across the chart’s surface area, a directional arrow appears, and the chart begins to fade and move out of view (Figure 15).
Figure 15. Initiating Chart Filtering
When the mouse is dragged an appropriate distance (roughly a quarter of the chart’s size), chart filtering becomes “activated.” This is indicated by the directional arrow becoming highlighted (Figure 16). Once the mouse is released, the chart is swiped out of view, then swiped back with the new filter applied. If mouse is released prior to activation, the chart bounces back into view without applying a new filter.
Figure 16. Chart Filtering Activated
Notice, as shown in Figure 17, the Compliance Summary Chart has changed to include “(PC)” in its title and the data presented differs from the last view.
Figure 17. Chart Filtering Completed
When filtering the chart’s view by manufacturer and industry (up or down), the model cycles through each available manufacturer, the entire industry, and the current manufacturer being evaluated. When filtering for the current manufacturer, the chart’s title displays an asterisk next to the manufacturer’s name. As modeling progresses, the compliance information will be updated as more technology is added to the current manufacturer, or the modeling system switches to analyzing another manufacturer, model year, or scenario. Similarly, when filtering the Compliance Performance Chart by model year (up or down), the model cycles through each model year and the current year being examined. As with other charts, filtering for the current year displays an asterisk in the chart’s title.
Figure 18 shows a comparison of different views when filtering the Vehicle Scatter Plot by manufacturer. Notice the asterisk next to General Motors. This indicates the data for the current manufacturer being evaluated is shown.[5]
Figure 18. Manufacturer Filtering Examples
All of the charts provided support filtering by regulatory class, however, only the Vehicle Scatter Plot and the Compliance Summary Chart support filtering by manufacturer. Filtering may also be triggered by using the keyboard’s arrow keys, pressing the left or right arrows (to filter by regulatory class) or up or down keys (to filter by manufacturer).
The charts may also be “zoomed” or “expanded” by double clicking on the chart’s area (Figure 19). This expands the selected chart to fit the entire contents of the model’s Session View, allowing for easier interpretation of the data.
Figure 19. Vehicle Scatter Plot - Zoomed View
Only the current scenario being evaluated, or the last scenario analyzed if modeling has completed, is available for viewing within the model’s Session View. However, users may interact with each chart while the compliance modeling process is still running as well as after modeling concludes.
During runtime, the CAFE Model produces several outputs, located in the user selected output path. Different types of modeling outputs are split into separate folders and are categorized as shown in the following list.
· reports-csv: Contains the various modeling reports the CAFE Model produced during analysis.
· debug-logs: Contains additional log files used during debugging of the model. At present, this folder provides debugging log files for the VMT model and the DFS/SR model.
The system generates five required and 11 optional modeling reports (in CSV format) during runtime, with some of the required reports being produced as “incremental” and “absolute” versions. In addition, the CAFE Model may be optionally configured to produce “reclassified” versions of the required reports, as well as split some of the larger files by scenario. The contents of these reports are discussed in greater detail in Appendix B of the CAFE Model Documentation. The following provides an overview of the available modeling reports.
· Technology Utilization Report: Provides manufacturer-level and industry-wide technology application and penetration rates for each technology, model year, and scenario analyzed. The results are disaggregated by regulatory class, as well as combined over the entire fleet. The system may be configured to optionally generate an additional “reclassified” version of this report.
· Compliance Report: Provides manufacturer-level and industry-wide summary of compliance model results for each model year and scenario analyzed. The results are disaggregated by regulatory class, as well as combined over the entire fleet. The system generates an “incremental” and an “absolute” version of this report and may be configured to optionally generate an additional “reclassified” version.
· Consumer Costs Report: Provides industry-wide summary of consumer-related costs for each model year and scenario analyzed, using discounting from the consumer’s perspective. The results are disaggregated by regulatory class, as well as combined over the entire fleet. The system generates an “incremental” and an “absolute” version of this report and may be configured to optionally generate an additional “reclassified” version.
· Societal Effects Report: Provides industry-wide summary of energy and emissions effects for each model year and scenario analyzed. The results are disaggregated by regulatory class and fuel type, as well as combined across all fuels and over the entire fleet. The system generates an “incremental” and an “absolute” version of this report and may be configured to optionally generate an additional “reclassified” version.
· Societal Costs Report: Provides industry-wide summary of consumer and social costs for each model year and scenario analyzed, using discounting from the social perspective. The results are disaggregated by regulatory class, as well as combined over the entire fleet. The system generates an “incremental” and an “absolute” version of this report and may be configured to optionally generate an additional “reclassified” version.
· Annual Consumer Costs Report: (Optional) This output file is similar to the Consumer Costs Report, except it further disaggregates the results by vehicle age.
· Annual Societal Effects Report: (Optional) This output file is similar to the Societal Effects Report, except it further disaggregates the results by vehicle age.
· Annual Societal Costs Report: (Optional) This output file is similar to the Societal Costs Report, except it further disaggregates the results by vehicle age.
· Annual Societal Effects Summary Report: (Optional) This output file is similar to the Annual Societal Effects Report, except it aggregates the results by calendar year. Note, the Societal Effects Report produces results for each model year considered during analysis. Conversely, the summary report summarizes the annual results by calendar year.
· Annual Societal Costs Summary Report: (Optional) This output file is similar to the Annual Societal Costs Report, except it aggregates the results by calendar year. Note, the Societal Costs Report produces results for each model year considered during analysis. Conversely, the summary report summarizes the annual results by calendar year.
· Vehicles Report: (Optional) Provides a detailed view of the final state of each vehicle examined by the model, for each model year and scenario analyzed. The system may be configured to optionally generate additional versions of this report that are split by scenario.
· Vehicles Diagnostic Report: (Optional, Diagnostic) Provides extensive diagnostic information for each vehicle model, including utilization, costs, and fuel economy improvements of each technology or a combination of technologies, as it applies to the specific vehicles. The system may be configured to optionally generate additional versions of this report that are split by scenario.
· Platforms Report: (Optional) Provides platform-level summary of compliance model results, providing a detailed view of the final state of each platform examined by the model, for each model year and scenario analyzed.
· Engines Report: (Optional) Provides engine-level summary of compliance model results, providing a detailed view of the final state of each engine examined by the model, for each model year and scenario analyzed.
· Transmissions Report: (Optional) Provides transmission-level summary of compliance model results, providing a detailed view of the final state of each transmission examined by the model, for each model year and scenario analyzed.
This section provides examples for configuring and running the CAFE Model sessions using various model types.
Example 1 – Configuring for Standard Compliance Modeling
This example demonstrates the steps necessary for configuring the modeling system to perform a regular Compliance Model run.
· Run the CAFE Model by clicking on the CAFE Model executable.[6] Read through the Warnings dialog box, and then click the OK button. Wait for the main CAFE Model window to appear.
· Select File > New Session to create a new modeling session. The Modeling Settings window appears. Note the errors at the bottom of the window; these indicate that the input files have not yet been selected.
· On the General Compliance Settings panel, select the Standard Compliance Model as shown in Figure 20 below.[7]
Figure 20. Select Standard Compliance Model
· Click on the I/O Settings panel to select the input files to use for modeling and the location for output files (Figure 21). Note that once all the input files have been selected appropriately, the error messages disappear.
· On the I/O Settings panel, users are also advised to change the output location.
· For this example, the selection of modeling reports is not changed.
Figure 21. Select Input Files
· The Runtime Settings panel is not used for this exercise.
· Click the Save button to save the modeling settings and load the input files (Figure 22).
Figure 22. Save Modeling Settings
· Once loading completes, click the Close button to return the main CAFE Model window. A new Compliance Model session, titled “Session 1” has now been created (Figure 23).
Figure 23. New Compliance Model Session Created
· Save the new session by selecting File > Save Session As.... Enter “demo.cmsd” in the dialog box that appears, then click the Save button (Figure 24).[8]
Figure 24. Save New Session
· After the session has been saved, notice the title of the session has changed to “demo” (Figure 25).
Figure 25. “demo” Session Saved
· Select File > Start Modeling to start the compliance modeling process. As the model runs, the progress of the Compliance Model is displayed in the CAFE Model’s Session View (Figure 26).
Figure 26. Modeling Progress from the Compliance Model
· After modeling has completed, the “Modeling Completed!” message appears at the bottom of the main CAFE Model window (Figure 27).
Figure 27. Compliance Model Completed
· Select View > Output Location to open Windows Explorer and browse to the location where model outputs for the “demo” session are saved.
· Close the session by selecting File > Close Session.
· Exit the CAFE Model by selecting File > Exit or proceed to the next example.
Example 2 – Configuring for “CO2 Compliance” Modeling
This example demonstrates how to take an existing session created in Example 1 – Configuring for Standard Compliance Modeling, and modify it to evaluate compliance with EPA’s CO2 standards.
· Run the CAFE Model by clicking on the CAFE Model executable. Read through the Warnings dialog box, and then click the OK button. Wait for the main CAFE Model window to appear.
· Select File > Open Session to open an existing modeling session. Select “demo.cmsd” in the dialog box that appears, then click the Open button (Figure 28).[9]
Figure 28. Open “demo” Session
· Once the session has been loaded, select View > Modeling Settings to bring up the Modeling Settings window.
· Click on the Runtime Settings panel and select the CO-2 option from the Compliance Program to Enforce section as shown in Figure 29.
Figure 29. Enable Compliance with CO2 Standards
· The rest of the panels are not used for this exercise.
· Click the Save button to save the updated modeling settings; then click Close, once saving completes.
· To prevent overwriting results from the “demo” session, select File > Save Session As... to save the modified session with a new name. For this example, the session was saved as “demo-co2.cmsd.”
· Select File > Start Modeling to start the modeling process. As the model runs, the progress of the Compliance Model is displayed in the CAFE Model’s Session View.
· Notice that the compliance-related information displayed in the model’s charts have changed from “CAFE” to “CO2” and the units have been updated from “mpg” to “g/mi” (Figure 30).
Figure 30. Modeling Progress for Compliance with CO2 Standards
· After modeling has completed, the “Modeling Completed!” message appears at the bottom of the main CAFE Model window.
· Select File > Exit to exit the model.
The following outlines some of the known issues within the CAFE Model’s user interface and provides possible workarounds. This list, however, is not comprehensive.
· The model may sometimes display minor visual artifacts when interacting with the charts in the model’s Session View.
· On rare occasions, the model’s GUI may stop refreshing during on-going analysis. That is, the charts displayed in the Session View will stop updating. There is no known workaround for this issue. Please wait for modeling to complete (a “Modeling Completed!” message will still appear at the conclusion of analysis), then restart the CAFE Model application.