We are now required to do additional reporting on our CO2 emissions as part of our corporate responsibility commitments. To do this, we need to know distances travelled by various transport modes.
For mileage expenses this is straightforward, as claimants enter number of miles anyway.
For flights we have the from/to airport codes, so it's possible to convert these to a distance.
That leaves us with trains (and other public transport) and taxis. Although we can add fields for from/to to these expense types, they're free text, so not much use if someone puts "home" to "office".
Is there any way to force these fields to be actual locations/postcodes?