I never saw any of this series. I wish I had, and unfortunately I've missed the chance to even catch up on iPlayer! But I don't need a documentary to see the stresses our ancient rail system is under. I can be within central London within an hour by train, and take a number of routes. Along most of these routes the state is clear to see (and feel the rattles if you're on an older train). Delays, posters, and general station maintenance are key factors in showing how bad it really is.