PCE counts handler

[Theodore-Chatziioannou]

We can currently extract link vehicle counts from Elara, however, to understand or analyse congestion effects, we need to be looking at PCE counts. This could be its own handler, or a switch in the LinkVehicleCounts one.

[fredshone]

my knee jerk preferance is for a stand alone LinkPCECounts handler. I think it is easier for users to understand and use, as opposed to passing options via the complex config form.

linkVehcileCcounts' is typically set as 'car', and/or bus. Not sure it even works with all`? If you ran with all you would also be returning trains etc, which might not be of interest. I think "all" might simply break the vent handlers factory.

As a hack could calc PCE from the above, ie (1 * car) + (2.8 * bus) etc. Elara already scales stuff as required (only cars).

If we still are happy for PCE to be calculated for individual modes eg LinkPCECounts:car and LinkPCECounts:bus then can simply add as a column to existing?