Is it 3 x 4 car 380's on the Neilston route off peak?
There's also a 4 car 380 diagram on the Shotts line to i'm sure.
Yes, the route is exclusively worked by class 380s between the peaks, actually during the peaks they tend to go onto Newton and Circle services more. My impression was that the 380s on the Neilston route was a direct transfer of the diagrams saved from the East Lothian routes going to 385s, although there is still one class 380 through on North Berwicks during the day I think. Isn't there also an additional 380 on the Inverclyde route these days having taken over a 314 diagram, or am I thinking about the 385 diagram?
Part of the issue with different units on different routes is that ScotRail's planners will also be responding to reported passenger numbers, and will diverting resources to best deal with that whilst also taking into account operational issues such as driver knowledge and capacity constraints. For example, the 4 car 380 that is still on the Shotts route all day is almost certainly entirely down to keeping 4 car formation on the 1718 ex-Central, which used to be 2 x 156.
The 385s on the Ayrshire routes may be the most logical choice when it comes to best utilisation of the units, due to their top speed and internal layout, but there will be other considerations too. How do they use the displaced class 380s - do they go onto Inverclyde or Cathcart routes? The other issue is that Ayr based drivers would have to be trained to drive the 385s, for which there will be cost. Is it worth that just to take them off the Cathcart line where at least all the drivers are familiar?