so, can anybody explain to me the logic , if there is any, as to where easements on railcards are allowed?
In general, easements are allowed in circumstances that make it very much worthwhile the granter of the easement doing so. Which means it brings them significant extra business (commercial) / save them popularity / votes (political) by making the decision.
Looking at commercial fare timing easements ...
The first thing the responsible
TOC▸ will look at is whether it will raise an objection from another TOC. Slightly far fetched, but would an 09:59 start from Grateley to London tempt car drivers from the hinterland away from the 10:19 Pewsey to London, so would Great Western Railway (
GWR▸ ) object?
Second thing - would the easement lead to a significant loss of revenue using the existing service at a higher price and dropping to the lower cost ticket if the easement was introduced?
Thirdly, would it make longer distance fares with the easement undercut higher short distance fares? For example, easements on the 08:49 Swindon to Westbury for fares beyond Chippenham cannot be offered due (I understand) to potential irregularities introduced to the local Swindon to Chippenham traffic.
Fourthly - there has to be a border time somewhere, and in order for a fare time easement to be granted, the grantor and consultees will need to be convinced that it's worthwhile moving the line. So you're more likely to find grants being made on infrequent services (such as the train that runs through from Swindon to Exeter and beyond before the normal start of rover time) rather than on a service that runs every hour and just happens to fall the wrong side of the lip at Grateley - "has to happen somewhere / train stops every few minutes" ...
Not all easements are conventional (i.e. just a few minutes stretch) ... I note some very early rover ones from Exeter to Barnstaple which are a way of making the rovers more useful / selling more while boosting traffic on a train that would otherwise be pretty darned quiet; it's really runs 'out' to form an incoming train and if it can get a bit of revenue, why not?
Political decisions on easements are interesting - I'm thinking of local councils on
ENCTS▸ cards for the buses. We see those decisions based on a multi-hour gap to the next service, making the 09:20 a great way into "Town" but the 11:50 being too late for pensioners who need to do their shopping and get home for lunch. And with politics so much is about the timing of when you ask for the easement in the election cycle. I suspect there are considerations within the franchise cycle to be looked at too ...
Edit: VickiS - Clarifying abbreviation