Defining the Base Case: Input Requirements
To function correctly, the model needs a set of input data that altogether define the base case scenario. The base case defines the status of a program in its current shape and form, without the implementation of the proposed policy or strategy.
Program Information - This consists of information on the base case scenario, where program characteristics are described.
Individual Information – This consists of information on the number of users the policy will affect. Usually this comprises the pool of employees participating as being part of a TDM program.
Trip Data – This includes information on mode shares, average trip length and
travel time by mode, and average vehicle occupancy.
This information is entered into a worksheet tab entitled “Base Case Scenario,” which is displayed in Figure 5.
Figure 5 TRIMMS – Base Case Scenario Worksheet
When entering the program information, the user can select the year the analysis is being conducted and all costs and benefits are immediately adjusted to current dollar values. Next, the user is directed to estimate the impact of several program strategies or policies. Following the literature on TDM strategies, impact evaluation is split into hard program