I've got a question that I've been wanting to ask for ages and this thread seems as better place as any to throw it in... Say there's a train that goes down a route maybe once a day (or worse, maybe once a week!), coming from a bus background it's pretty open to people swapping duties etc. Now I'm thinking if you're rostered to do this run - let's say it's on a late shift for example - and you swap it because you don't like lates or other reason, might be childcare/whatever, now say it's a fairly large depot (I'm thinking something along the lines of Northern Sheffield with Thrybergh line etc) and it only comes round on your rota once or twice in the six month period where route knowledge expires (I believe?). If you swapped it away for something better/rest day swap etc then who's responsibility does it become to keep the route knowledge up? Given it was your choice to swap it away etc I'm assuming you'd be encouraged to pick it up again in your own time rest day or whatever? Apologies for the long ramble, it's a very 'what if?' question but it's always intrigued me.