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Surface Transportation Efficiency Analysis Model (STEAM)User Manual

4.0  User Interface

This chapter explains the user interface for the STEAM 2.0 software. The program is a windows application that can run under Windows 95, 98, 2000 or NT. The areas covered in this section include:

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4.1  Installing STEAM 2.0 Software

STEAM 2.0 has an installation program that installs the proper files on a user's hard drive in order to run the program. The install package is a regular Windows Install-Shield program that is used in the majority of Windows software and is familiar to most Windows users. Close all other programs before beginning the installation process in order to avoid any conflicts with shared files. STEAM 2.0 Release Version 1.0 will only run under Windows 95, 98, 2000 or NT operating systems.

To run the install program, the user executes the "Setup" command from Windows which loads the setup program and prompts the user for specific information. Initially, the setup program prompts the user to select a directory for the STEAM 2.0 program with a default directory "C:/Program Files/STEAM 2.0 ". Exhibit 4.1 shows the screen displayed for the STEAM 2.0 setup. By selecting the setup button the install package copies the necessary program files into the proper directory and the necessary common files into the Windows (WinNT) directory.

Exhibit 4.1  Install Screen for STEAM 2.0 Setup

Install Screen for STEAM 2.0 Setup

To run the STEAM 2.0 program, run the "STEAM 2.0.exe" file from the Windows Explorer.

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4.2  STEAM 2.0 Program Screen

Exhibit 4.2 presents the STEAM 2.0 program screen which the user works with to run a benefit/cost analysis. The main screen is divided into two panes: an tree navigation pane (on the left) and a display window (on the right). The user will make a selection from the tree navigator by clicking or double-clicking a specific item which will activate the display window to present information for that selection. The contents of the tree navigator are changed by making a selection from the "Edit Menu" option.

The program screen has six main menu categories: File, Edit, Run, Results, Tools and Help. Exhibit 4.3 shows the full structure of the menu options under the categories. A brief description of each of the options is provided below.

File/New - Creates a new scenario to run the STEAM 2.0 analysis and sets the input parameters to the default values.

Exhibit 4.2  STEAM 2.0 Program Screen

STEAM 2.0 Program Screen

Exhibit 4.3  STEAM 2.0 Menu Structure

STEAM 2.0 Menu Structure

File/New - Creates a new workplace, with default parameter settings, from which to create a new transportation analysis.

File/Open - Displays the "File Open" dialog box to load an existing scenario file that was created earlier and allows the user to update information or run the analysis. STEAM 2.0 is backwards-compatible with STEAM scenario (.scn) files. Once loaded, the scenario file must be updated and saved with the updated matrix formats and with the district/accessibility parameter settings correctly specified.

File/Close - Closes the file.

File/Save - Displays the "File Save" dialog box that saves the current scenario information to a file that can be loaded and used at a later time.

File/Save As - Displays the "File Save As" dialog box and saves the current scenario information under the new file name specified.

File/Print - Prints the scenario report which contains the scenario output, input parameter assumptions, and market sector definitions.

File/Exit - Closes the application.

Edit/Scenario Description and Districts - Displays the screen to input a descriptive title for the current analysis scenario, and prompts user to provide the name of the District definition file.

Edit/Market Sector - Displays a "Market Sector" dialog box which list the existing market sectors in the current scenario and allows the user to add a new market sector, delete a market sector, modify a market sector, or cancel any action.

Edit/Model Parameters - Changes the information displayed in the tree navigator to a list of model parameters that can be selected and changed by the user.

Edit/Improvement Costs - Changes the information displayed in the tree navigator to a list of improvement cost categories that STEAM 2.0 users can select to input the improvement costs being analyzed in the scenario.

Edit/Transit Service Changes - Changes the information displayed in the tree navigator to a list of transit service changes that can be input by the user as a result of the proposed improvements.

Edit/Ranges for Risk Analysis - Changes the information displayed in the tree navigator to a list of variables for which risk analysis ranges can be set by the user.

View/Toolbar - Displays standard Microsoft editing toolbar.

View/Status Bar - Displays standard Microsoft status bar at the bottom of the screen.

Run/Check Data Inputs/Check Input Files - This menu item runs the routine that checks data input files for proper format and valid ranges. The output of the data checking routine is stored in the "Data Check Log" which can be viewed in the menu selection described below.

Run/Check Data Input - This menu item displays the most recent results of the "Check Input Files" routine. Any errors in file formats or in valid ranges will be displayed.

Run/Estimate Run Time/Without Risk Analysis - This menu item estimates the run time necessary to perform the benefit/cost analysis without the risk analysis procedure, based on the market sector information contained in the current scenario. A dialog box is displayed that presents the time estimation. STEAM 2.0 uses performance benchmarks derived from previous STEAM 2.0 analyses to generate time-to-completion estimates. Therefore the time estimates from the first few STEAM 2.0 analyses are unreliable and should be ignored.

Run/Estimate Run Time/With Risk Analysis - This menu item estimates the run time necessary to perform the benefit-cost analysis with the risk analysis procedure based on the market sector information contained in the current. A dialog box is displayed that presents the time estimation.

Run/Run Model - Presents a choice of two sub-options: Run Model With Risk Analysis and Run Model Without Risk Analysis.

Run/Run Model/Run Model With Risk Analysis - Runs the risk analysis module with the market sectors and model parameters specified in the current scenario and risk parameters' variation ranges specified by the user.

Run/Run Model/Run Model Without Risk Analysis - Runs the benefit-cost analysis with the market sectors and model parameters specified in the current scenario.

Results/Show Results of Current Scenario - Displays the results contained in the output file specified for the current scenario.

Results/Show Risk Analysis Results - Changes the information displayed in the tree navigator to a list risk analysis output variables that the user can select to view the probability ranges for the scenario.

Results/Show Auxiliary Analysis Results - Presents results of district-level analysis and results by market sector These results are presented in text, spreadsheet-compatible and database-compatible formats.

Tools/Convert STEAM 1.0 Files to STEAM 2.0 - Invokes menu for a utility that converts matrices in STEAM 1.0 "square" format to origin-destination-value format.

Tools/Reporting Options - Invokes menu for users to select a text editor and spreadsheet program for viewing STEAM 2.0 outputs.

Help/Contents - Displays the "Contents" window of the STEAM 2.0 help file.

Help/Search - Displays the "Help Search" window that allows the user to search the STEAM 2.0 help file for specific terms.

Help/Help on Help - Displays the "Using Help" window that provides guidance in using Windows help programs.

Help/About STEAM 2.0 - Displays the information about the program

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4.3  Creating, Loading, and Saving Scenarios

STEAM 2.0 uses the term "scenario" to define the benefit/cost analysis of a given set of transportation system improvements. Users may decide to change specific assumptions and therefore would want to create a different scenario to perform a second analysis. STEAM 2.0 allows users to create multiple scenarios that can be saved, loaded, and run at later times without going through the entire process of defining market sectors and adjusting model parameters.

The assumptions, output, and input file locations for each scenario are stored in a scenario file. Under the "File" menu, the "New", "Open", "Save", and "Save As" options allow the user to create, load, save, and save the scenario under a different file name. These options work the same as similar options in other Windows programs. Standard Windows "Open File" dialog boxes allow the user to locate files in specific directories. Exhibit 4.4 shows the dialog box that is displayed when one of the options is selected.

The default scenario file extension is ".bsn". However, the file can be saved using any extension that the user chooses.

Exhibit 4.4  STEAM 2.0 File Dialog Box

STEAM 2.0 File Dialog Box

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4.4  Defining Market Sectors

STEAM 2.0 analyzes investment decisions by examining individual market sectors that represent portions of the transportation demand on the network. The travel demand can be divided into any number of market sectors and can be divided by mode, trip purpose, or time of day depending on the output of the travel demand model.

Initially, a new market sector is defined by selecting the "Market Sector" option under the "Edit" menu. A market sector dialog box is displayed and lists the existing market sectors in the current scenario. The dialog box allows the user to add a new market sector, delete an existing market sector, modify an existing market sector, or cancel without any action. The maximum number of market sectors that can be used in one scenario is 200.

The market sector dialog box is shown in Exhibit 4.5.

Exhibit 4.5  Market Sector Dialog Box

Market Sector Dialog Box

Once a market sector is added to the scenario, select one of the three branches in the tree navigator: "Market Sector Information", "Market Sector File Names", or "Market Sector Other Changes Files" which will display the market sector input screens displayed in Exhibits 4.6, 4.7, and 4.8. These screens are used to input information about the market sector in order to run the investment analysis.

The "Market Sector Information" screen allows the user to name the market sector, specify vehicle occupancy and expansion factor, and select mode of transportation and speed relationship. Each input variable is defined below:

Market Sector Name. The market sector name is used simply to keep track of individual market sectors and can be up to 28 characters.

Vehicle Occupancy. The vehicle occupancy is the average number of people per vehicle and is used to estimate the number of vehicle trips for a given market sector based on the market sector person trip tables. Separate occupancies can be provided for the Base Case and the Improvement Case.

Expansion Factor. The expansion factor is used to expand the trip tables to an annual value. A market sector that represents daily work trips may have an expansion factor of 250 to represent all work days for a given year.

Mode of Transportation. This input option allows the user to select one of eight mode choices that include: auto, truck, carpool, local bus, express bus, light rail, heavy rail, and other. Modes that are not currently defined such as bicycle or walking can be put in the "other" category.

Speed Relationship. Allows the user to select from four speed relationships as a function of AWDT/C (average weekday daily traffic/capacity). The four speed relationship choices are Daily, Peak, Off-peak, and the coded speeds in the free-flow speed field.

Value of time. STEAM 2.0 uses the in-vehicle and out-of-vehicle value of time to calculate user benefits for each market sector. The default values for the mode chosen appear in the text box.

Calculate Accessibility Check Boxes. Selecting the "Calculate Accessibility by Time Thresholds" and/or the "Calculate Accessibility Index" Option enables one or both accessibility analyses. Note that the accessibility thresholds are set in the "model parameters" screen, under "accessibility and aggregation parameters". The dispersion parameter for the accessibility index calculation may be set in this model parameter screen as well.

Exhibit 4.6  Market Sector Information Screen

Market Sector Information Screen

The "Market Sector File Names" screen allows the user identify the input file locations for the current market sector, determine whether or not to run the network analysis, and whether or not to use travel time estimations. Three check boxes are located at the top of the screen which allow the user to run base or improvement network analysis (if these boxes are not selected the user cannot input file names for the network input files). The "Ignore Network Travel Time Analysis" check box specifies that the market sector will not use any travel time estimation for calculating benefits. This option is generally used for transit market sectors that do not have existing networks to estimate travel times (if this option is selected, the network input and output files become inactive).

Users also may provide a factor to convert trips in production and attraction format to origin/destination format. This feature is used with the district-level reporting feature. Users wishing to report benefits to resident trip-makers should select the aggregation by origin district feature under the model parameters menu. If resident home-based work trips is the market sector chosen for aggregation to districts, then trips should be expressed in P/A format and the appropriate factor applied. Users wishing to aggregate results by destination district should select the aggregation by destination option under the model parameters menu. If the aggregation by destination should consider benefits to non-resident trip makers only, then trips should be expressed in P/A format and the appropriate factor applied as well.

An explanation of each of the files and options is provided below:

Run Network/Don't Run Network Option. This option allows the user to select whether or not to run the network analysis. Once a network analysis has been performed on a particular network, there is no need to re-run it unless changes to the network have been made. STEAM 2.0 will run significantly faster if the network analysis is not re-run for the same network.

Network Input File. This input box provides the location of the network file. The format of the file is described in the "Input File" section of this report. The default name extension for this file is '.nwk'.

Output File. This input box provides the location of the network output file which is used later in the Trip Table analysis for estimating travel time benefits. This file is an intermediate binary file that is only used by the STEAM 2.0 program. The default name extension for this file is '.ttf'.

Trip Table File. This input box provides the location of the travel demand file. These files are used in estimating benefits and costs occurring on a particular network. The format of the travel demand file is described in the "Input File" section of this report. The default extension for this file is '.btp'.

Zonal Information (Centroid) File. This input box provides the location of the zonal information file which contains information on the zones specified for the travel time analysis. Each zone is identified with the corresponding node location. Optionally, the district number, and population and employment may accompany the centroid number on each record. A zonal information file is necessary for each market sector and it is used in both the base and improvement cases. All market sectors require this file. The default name extension for the centroid file is '.bcr'.

Production/Attraction factor. STEAM 2.0 uses the P/A factor to convert a travel demand file in production/attraction format to origin/destination format. This allows STEAM 2.0 to report district-level results for resident trip makers. STEAM 2.0 applies the percentage entered to the P/A interchange, in order to create an origin/destination interchange. The balance of the P/A interchange (100- the percentage entered) is transposed to create trips from the destination to the origin. Both types of trips are attributed to the district of origin. If the P/A factor is set at 100%, the table is treated as an origin/destination trip table, i.e., no changes to the trip interchanges are made.

Exhibit 4.7  Market Sector File Locations

Market Sector File Locations

The "Other Changes File Names" allows the user identify in-vehicle and out-of-vehicle travel time matrices for transit, or other modes whose travel times cannot be skimmed by STEAM 2.0 from the highway network file. This screen also allows users to input out--of-pocket cost matrices for fares, parking costs and other O/D-based costs. Once the user selects the check box corresponding to the time/cost matrix desired, the Base Case and Improvement Case file dialog boxes are enabled, and the user can identify the name and location of the appropriate input files. The format for these files is described in Chapter 3.

When evaluating transit user benefits (costs), services that provide transit connectivity between zones in the base case and not the improvement case (or vice-versa) should be treated with care. Some analysts prefer to fill zero-value interchanges for time or cost with a value reflecting an average or low level of transit service for the corridor or district in question.

Exhibit 4.8  Market Sector Other Changes Files

Market Sector Other Changes Files

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4.5 Defining Districts

STEAM 2.0 reports transportation user impacts for the region and by user-defined districts. These districts are aggregations of traffic zones, and may correspond to county, census tract or other boundaries describing regional sub-markets.

The user-defined districts are defined in two files: the zonal information file and the district file. If the user wishes to report results by district, the zonal information file must contain the district number corresponding to each traffic analysis zone in the second field of each record (See Chapter 3). Each traffic zone can be assigned to at most one district. If no district-level reporting is desired, then only the traffic zone (centroid number) itself is required in the zonal information file. Users also associate a district number with a name (for example, 100 "South County") in the district file. Users assign the district file to the scenario through the "Edit Scenario/Description and Districts" menu option.

Scenario results are reported by district in a district report. This report is accessed through the "Results/Show Current District Results" menu option.

Figure 4.9  Selecting a District File

Selecting A District

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4.6  Developing an Accessibility Analysis

STEAM 2.0 provides users with the option of evaluating regional accessibility resulting from transportation investments. Accessibility is a measure of proximity between people and places, measured over a transportation system. It can be used in STEAM 2.0 to assess the effectiveness of alternative transportation investments in increasing employment, shopping or other opportunities for geographic (and/or demographic) .submarkets within the region.

An accessibility analysis requires data on population and employment for each zone and a definition of the aggregations of zones, or districts used. The zonal population and employment data are stored in the zonal information file. The districts, which are aggregations of traffic zones such as counties or census tracts, are also defined in the zonal information file. Unique names may be given each district; this information is stored in a separate file, the district file, as described above.

The accessibility analysis reports the number and percentage of regional jobs or persons within a certain time threshold of each district. Users may set up to seven travel time thresholds for the accessibility analysis in the "Edit/Model Parameters" .menu option. Results may be viewed under "Results/Show Current District Results" menu option. STEAM 2.0 also develops an accessibility index, a single figure summarizing results over the entire region.

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4.7  Changing Parameter Values

The STEAM 2.0 benefit/cost analysis uses a number of different parameters such as value of time, emission rates, and accident costs to perform the investment analysis. The program has default values for these input parameters; however, users may wish to change the input values to reflect a specific location or situation. All parameter values can be changed by the user, and are saved in the scenario input file.

To change input parameter values, the user must first select the "Model Parameters" option from the "Edit" menu. This changes the information in the tree navigator and displays a list of parameter names as shown in Exhibit 4.10. The user needs to click or double click a particular item from the tree navigator to show the parameter information in the display window. In Exhibit 4.10, the "Non-Fuel Highway Cost" parameter has been selected, displaying the Auto and Truck values. The user can change these values by overwriting the existing value. New values are saved when the scenario file is saved.

Exhibit 4.10  Model Parameters ( Non-Fuel Highway Cost)

Model Parameters (Non-Fuel Highway Cost)

A restore default button is provided in the top right corner of the display window which will restore the parameters on the current screen to their default values. A list of the model parameters is provided below. Descriptions of selected parameters and the source for their default values are provided in Appendix A: Glossary of Terms.

Model Parameters

Users may set the value of time in two separate locations within STEAM 2.0: 1) in the market sector information screen and; 2) in the model parameter screen. These settings serve separate functions. The settings in the parameter screen set the market and mode-specific in-vehicle and out-of-vehicle values which appear as defaults in the market sector information screen. The values set in market sector screen are the values actually used by STEAM 2.0 in the analysis.

Users set the accessibility thresholds, dispersion parameter and the orientation of district aggregation through the accessibility and aggregation parameter screen. Up to eight travel time thresholds may be set by the user for the accessibility analysis. The dispersion parameter, used for calculating the accessibility index, specifies the sensitivity of the index to congestion and longer-distance trips. Higher values indicate a greater sensitivity to higher travel times.

Examples of non-mileage based external costs include noise, travel delay, and fugitive dust during construction. Also, the STEAM 2.0 user can use the parameters for other mileage-based external costs to account other external costs.

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4.8  Specifying Improvement Costs

Capital cost values are necessary in calculating a benefit-cost ratio for the proposed improvements. The user enters the capital costs, the midpoint of construction, year of opening, useful life, and salvage value for all improvements being analyzed. Net costs, the costs of the improvement case over and above those of the base case, should be entered as capital costs. STEAM 2.0 allows each scenario up to 5 different capital investments.

To enter improvement cost information, the user must select the "Improvement Cost" option from the "Edit" menu. The user then selects "Capital Cost Items" from the tree navigator. Exhibit 4.11 shows the Improvement Cost screen which is used to enter the capital cost information.

Exhibit 4.11  Improvement Cost Screen

Improvement Cost Screen

The following information is entered for up to five items:

Capital Costs. This is the full cost of the capital improvement, which includes any engineering studies, right-of-way acquisition and all construction expenditures. For multiyear projects, capital costs include all expenditures made from start to completion. This variable is in dollars.

Midpoint of Construction. This is the year that falls in the mid point of the construction period. For single year construction projects the midpoint of construction would be the same as the year of opening.

Year of Opening. This is the year that the improvement project is planned to be completed and opened for use.

Useful Life. Useful life is the estimated number of years that a project can be used without requiring major reconstruction of the facility.

Salvage Value. This is the remaining value of the investment at the end of its useful life.

External Cost of Construction. The external costs to transportation users or non-users that occur as a result of the construction process.

If no capital cost items are specified in the scenario, a benefit analysis is performed that estimates the benefit or costs to highway and transit users.

Other changes in operating and maintenance costs are specified in the second capital cost item screen displayed in Exhibit 4.12. These costs would represent the annual cost of operating and maintaining a new highway if the improvement was to construct a new highway.

Exhibit 4.12  Other Operating and Maintenance Cost Screen

Other Operating and Maintenance Cost Screen

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4.9  Transit Service Changes

The STEAM 2.0 benefit-cost analysis allows the user to input transit service changes estimated by the user in order to calculate changes in transit costs. There are three types of transit service changes that can be specified: Transit VMT, Transit Vehicle Hours, and Transit Peak Vehicles. Exhibit 4.13 shows one of the three screens to enter the transit service changes.

To display the transit service changes screens, the user needs to select the "Transit Service Changes" option from the "Edit" menu and then select either "Transit Vehicle Miles", "Transit Vehicle Hours", or "Peak Vehicles" from the tree navigator.

All three transit service changes (vehicle miles, vehicle hours, and peak vehicles) can be specified by the user but the changes and the costs associated with the changes must be additive because all three costs will be included in the analysis.

Exhibit 4.13  Transit Service Changes

Transit Service Changes

Transit service changes are entered in miles, hours, and vehicles. A description of the three service changes is provided below:

Transit Vehicle Miles. The total annual change in transit vehicle miles that occurs as a result of the highway or transit improvement.

Transit Vehicle Hours. The total annual change in transit vehicle hours that occurs as a result of the highway or transit improvement.

Peak Vehicles. The average change in transit peak vehicles that occurs as a result of the highway or transit improvement.

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4.10  Defining Risk Analysis Input Ranges

To run the risk analysis procedure on the investment scenario, the user must define ranges for input variables. The input value ranges determine the high and low points for the input variable and the shape of the distribution curve between the high and low points. A log-normal distribution is used to determine the shape of the curve for all input variables.

In order to set the risk analysis input ranges, the user must select "Ranges for Risk Analysis" option under the "Edit" menu. This will display a list of input variables that risk ranges can be specified in the tree navigator. By selecting one of the input variables the risk input screen is created in the display window.

Exhibit 4.14 shows the Input Variable Risk Analysis screen. The user can enter the high value for the input variable. Most of the input variables use a risk factor which is a factor applied to all of the input variables in that category. An example is the HC emission rates. A factor of 2.5 means that the high value for all HC emission rates is 2.5 times the average values specified in the Model Parameter screens. This is applied to all 13 HC emission rates by speed increment. The low value is calculated by the program based on the log- normal distribution and the high and mid points.

Exhibit 4.14  Defining Risk Analysis Ranges

Defining Risk Analysis Ranges

To graph the curve of the distribution of the input values, the user must select the "Graph" button. Similar to other input screens, a "Restore Defaults" button is provided that resets the input variable risk range to the default values. In addition, at the bottom of the screen are "Non-Cumulative" and "Cumulative" buttons which change the graph from a histogram to a cumulative probability distribution curve. The cumulative probability distribution curve is shown in Exhibit 4.15.

Exhibit 4.15 Cumulative Distribution Curve for Risk Analysis Ranges

Cumulative Distribution Curve for Risk Analysis Ranges

Finally, the number of iterations the risk analysis procedure runs must be specified. The "Number of Iterations" is the number of times that the analysis cycles through the benefit cost estimation using different input values determined by the probability curves and a Monte-Carlo simulation.

To set the number of iterations for risk analysis, the user must select "Number of Iterations" in the tree navigator. Exhibit 4.16 shows the screen for changing the iteration value. Risk analysis iterations can be set from 100 - 2000 with the default value at 2000.

Exhibit 4.16  Number of Iterations for Risk Analysis

Number of Iterations for Risk Analysis

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4.11  Checking Input Data Files

STEAM 2.0's data checking routine identifies out-of-range values and formatting errors that will prevent STEAM 2.0 from executing successfully. In order to run the data checking utility, the user must first create or load the scenario (.bsn) file with the all the market sectors and input files specified. Once the scenario file is completed, the user can run the data checking utility by selecting the "Check Data Input Files" sub-option under "Check Data Input Files" option of the "Run" menu. The data checking utility may take a minute or two depending on the number of market sectors specified.

Once the data checking utility has been run, the result log can be viewed by selecting the "View Data Check Log (for most recent data check)" sub-option under the "Check Data Input Files" option in the "Run" menu. The log is for the most recent run of the data check which will be overwritten when another data check is performed. Exhibit 4.17 shows a sample data check log for a scenario that was specified correctly, with all the input files are in the proper format. Exhibit 4.18 presents a sample data check log showing the error messages that occur when the network file is not in the correct format.

Exhibit 4.17  Viewing Data Check Log

Viewing Data Check Log

Exhibit 4.18  Viewing Data Check Log with Error Message

Viewing Data Check Log with Error Message

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4.12  Estimating Run Time

To estimate run time, a scenario must first be defined and saved with all the markets sectors included. Once this has been done, select "Estimate Run Time" from the "Edit" menu. Chose either "Estimate Run Time Without Risk Analysis" or "Estimate Run Time With Risk Analysis" depending on which analysis is desired. STEAM 2.0 calculates run time based on the number of market sectors centroids, links and the speed of the computer. In order to obtain reliable benchmarks of the computer speed the user is advised to run a small demo scenario with the risk analysis option. Computer speed benchmarks will be permanently saved by the system and then applied to all other scenarios that the user will create. Exhibit 4.19 shows the message box reporting the run time estimation.

Exhibit 4.19  Estimating Run Time

Estimating Run Time

Network travel time estimations are the most time consuming process in the benefit-cost analysis. If the user is re-running a scenario that does not change previous travel time estimations or if you have market sectors that use the same networks, there is no need to run the network travel time estimations. Skipping travel time estimation will significantly reduce the model run time.

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4.13  Performing An Investment Analysis

To perform an investment analysis, the user must first define the scenario with all the market sectors included and adjust any parameter values that may apply to the run. The scenario file needs to be named prior to running the analysis.

Once the scenario has been properly defined, the user begins the analysis by selecting the "Run Model" option under the "Run" menu item. The user then selects the "Run Model Without Risk Analysis" sub-option, or the "Run Model With Risk Analysis" option. Exhibit 4.20 shows the status screen displayed when the program is running.

Exhibit 4.20  Running STEAM 2.0 Analysis

Running STEAM 2.0 Analysis

The analysis can be stopped by selecting the "Cancel" button on progress screen. The area on the upper left-hand corner of the screen indicates the status of the analysis, including the stage of the analysis and an estimate of the time remaining.

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4.14  Viewing Results

Once the benefit-cost analysis has been performed, STEAM 2.0 allows the user to view the output results of the current scenario and the risk analysis output ranges. As described in Chapter 3, scenario results are stored in binary archive with .bsn extension. In addition to output results, the file contains the input assumptions that were used to produce the results.

To view the main scenario output file, the user must select the "Show Current Scenario Results" option from the "Results" menu item. Exhibit 4.21 shows the screen that displays the output file for a given scenario. Scroll bars allow the user to move vertically and horizontally through the file. The viewer simply displays the contents of the output file but does not allow the user to edit the file.

Exhibit 4.21  Viewing Scenario Output File

Viewing Scenario Output Files

To view the output for selected variables from the risk analysis, the user must select the "Show Risk Analysis Results" option from the "Results" menu. This action displays a list of output variables in the tree navigator. By selecting one of the output variables in the tree navigator, the range of results for that variable is graphed in the display window.

The top of the screen displays the mean and median values for the output variable. On the right side of the graph presents the probability values. Similar to the input risk range screens, a "Non-Cumulative" and a "Cumulative" button is provided to allow the user to switch between the two types of graphs. Exhibit 4.22 shows the non-cumulative graph for the total user benefit result.

Exhibit 4.22  Non-Cumulative Total User Benefit Risk Analysis Results

Non-Cumulative Total User Benefit Risk Analysis Results

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4.15  Using Tools

STEAM 2.0 provides two utilities under the Tools menu: 1) a STEAM 2.0 matrix conversion routine; and 2) a select reporting options.

The matrix conversion routine converts files in square matrix format used by STEAM 2.0 to the origin/destination/value format used by STEAM 2.0. The dialog under the "Tools" menu option prompts the user to identify the STEAM 2.0 matrix name and location, and a STEAM-format centroid file. STEAM 2.0 creates a new matrix file, with a .btp extension. STEAM 2.0 also creates a new zone information file, with zeros filled in for columns 2-4, corresponding to the district, population and employment data. Exhibit 4.23 depicts the user interface for this conversion routine.

Exhibit 4.23  Converting STEAM 2.0 Matrices into Origin-Destination-Value Format

Converting STEAM 2.0 Matrices into Origin-Destination-Value Format

The scenario report file, and all of the district and market sector files can be viewed using common text editors and spreadsheet programs accessed from STEAM 2.0. To access these files through STEAM 2.0, users must specify the path and filename for the text editor and spreadsheet application they wish to use. The Windows Explorer "Tools/Find" feature can be used as an aid to find the executable files needed to view the outputs. Also, users can specify the number of columns per row of output to display, in order to configure the text editor-compatible files (.mkr, .dkr) so that the output remains aligned with column headings on a single row of output. Both the spreadsheet-compatible (.dkx,.mkx) and database-compatible (.dkd,.mkd) files may be viewed from the spreadsheet application. Exhibit 4.24 presents the application selection screen.

Exhibit 4.24  Selecting a New Text Editor and Spreadsheet Application for Viewing Scenario Results

Selecting a New Text Editor and Spreadsheet Application for Viewing Scenario Results

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