10.19.2 Economic Evaluation: Rule of a Half

The classical rule of a half for calculating the consumer benefit of network/trip matrix 1 compared to network/trip matrix 2 may be written as:

Equation 10.1

This may be calculated by inputting the 4 relevant trip matrices – T1, T2, C1, C2 – as input files 1 to 4 respectively (recalling that cost matrices may be calculated as described in Section 15.27.4) and then creating the internal matrix via the equation:

The consumer benefits may then be viewed per cell, per origin/destination or in to using master options 8 and 9.

Note that to “dump” the total benefit into an external file, e.g. as part of a iterative process involving forecasts for a series of future years, you may make use of the facilities described in 10.14.

More simply the R.O.H. calculations are available as part of a standard batch file; see 10.20.8.