Do many in Wedtbury work on the railway then?
From a
Railway FAQ▸ from StagecoachThe UK▸ rail industry employs more than 190,000 people, from train drivers and station staff to those responsible for managing and maintaining the network’s 20,000 miles of track.
That's 1 in 315 of the population. Westbury's population around 15,000 (data set about 7 years old, like the Stagecoach quote) which means that if it were at the Bristish average, just under 50 people there would work in the rail industry. I'm not sure what the numbers actually are, though, nor how much above average a town would need to be if you want to consider it a "railway town".
Historically, the rail industry employed many more staff.
These days, a service of (say) 8 round trips a day with a journey of 45 minutes each way requires 4 staff members on a daily basis - double that to 8 to allow 7 day working, holiday, sickness, training, etc.; the number goes up to (say) 12 to 15 by the time you add maintenance staff, cleaners, etc ... and then there's the whole question of track and right of way care which may or may not count "against" the service depending on what else os sharing the track.
A hundred years ago (say) you would have been looking at two trains to operate the service due to additional needs of the locomotive, and slower runs with more intermediate stations, and a third crew member on trains. Those stations would all have ben staffed ("more heavily staffed" for stations that remain staffed to this day) and a service of the same number of trains would have required three times the staff at least. And there were more services about (or, rather, services were spread over more lines, but much more thinly for the most part).
I started to write this paragraph to give voice to there being a difference between current and historic perception of a "railway town" but not sure where it's leading ...History encourages me to believe that operation railway staff lived within walking distance of their base / depot. These days, I note significant flows of railway staff travelling to work by train. And by car too; until we have a 24 hour railway, the driver and conductor / manager / guard of the first train need to get to it, after all, and buses operate a much more limited day than trains for the most part. The historic clustering of rail staff into "rail towns" seems to have changed as staff disperse.
Westbury - the example I've chosen to follow up on, dates back to a settlement way before the railway came which was situated some distance from the current station / yards / operating point;it was a target destination of the railway builders - a minor one, but certainly not a spot in the countryside which Swindon was when the railway came. But over the years, it has looked very much to the railway.
Perhaps the best judgement is not on raw data from the head, but in the heart. If a town considers itself to be a railway town, then it IS one? 
