Great Western Coffee Shop

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Journeys from Totnes, Paignton, Torquay, Torre, Newton Abbot, Teignmouth, Dawlish, Dawlish Warren and Starcross to stations north of Tiverton Parkway may travel via Exeter St Davids. This easement applies in both directions.

Can anyone explain to me the purpose of this easement. Or what rule it is trying to overcome?

On a more general note, I can understand why easements exist. However, I am less convinced at the presence of what I would call negative easements. Once someone has identified via the routeing guide that a journey is permissible, are they expected to trawl through many pages of easements on the off chance of finding a negative easement that prohibits the journey they wish to take. That sounds extremely customer unfriendly to me.

Here's an example:-

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Customers travelling from Evesham and Pershore via Swindon may not travel via Worcester Shrub Hill. This easement applies in both directions.

And here's an example of a negative easement that doesn't appear to be necessary as it would break the rules of doubling back:-

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Customers travelling from Swaythling to Southampton Central and beyond may not travel via Southampton Airport Parkway. This easement apllies in both directions.

Finally, some are just pure gobbledegook:-

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WO4350 to allow doubleback when the error is 74 or 75 Ditton Marsh to Waestbury via Warminster

The easements file of the National Routeing Guide is the written text form of various bodges to the electronic journey planner. Many easements are written not to give greater or lesser flexibility to the passenger but to overcome bugs.

Good timing of this at the time when Whiteball Tunnel is closed.

Southampton Central and Southampton Airport Parkway are both in the same routeing group, so doubling back is normally permitted between stations within the group (for interchange purposes only).

Although given that Swaythling and Airport Parkway are only 70 chains apart, the 3 mile rule could be used on the shortest route (as the routeing guide has not been referred to yet)...

Hang on ... I think this answers a question in another thread. Trowbridge and Westbury are in the same station group (I just checked!) so that Melksham - Bradford-on-Avon / Bath Spa / Bristol Temple Meads etc passengers can double back at Westbury. The context of this was for customers in Wheelchairs which (platform to platform) at Trowbridge is all around the streets, but Westbury has lifts.   Have I got that right?

That is my understanding of this text at the bottom of Page F8 in "The Routeing Guide in Detail":
This can also be confirmed by using journey planners, but adding a Via station (see attached image).

Oh dear! Another can of worms opened up... so Melksham to Bristol via Westbury IS a valid route.

While looking at Brucey's reference in "The National Routeing Guide in Detail", I noticed that page F7 seems to give a totally bogus example, as the routeing points for Solihull are Stratford Group, Tyseley and Warwick. Nevertheless NationalRail.com does allow Solihull-Stratford via Moor St on a single ticket  :o How does that avoid being a victim of the doubling-back rule?  ??? ??? ???