I've seen a number of examples of this in the past. It's usually caused by the fact that the Street View car will only take fresh pictures as the vehicle is moving. So if it's approaching the barriers as they've just gone down, it'll take photos as it draws up to the line, stop, then resume taking pictures once the car is on the move again.
Some that I've found in a short space of time:
http://goo.gl/maps/kjTfT - Attenborough village.
http://goo.gl/maps/fYu74 - The same view from the other side, at the station entrance.
http://goo.gl/maps/Rju1Q - Barton Lane, Chilwell - leading to Attenborough Nature Reserve.
http://goo.gl/maps/IX8mb - Again from the other side (anyone who lives/works/regularly drives past these barriers will know how busy the Nottingham MML branch is).
http://goo.gl/maps/E2QIc - MML Nottingham branch again from Meadow Lane in Long Eaton.
http://goo.gl/maps/MZKQ4 - Lock Lane on the Castle Donington line (Stenson Jn - Trent Jn)
http://goo.gl/maps/jpbly - St Albans Rd in Bulwell, next to Bulwell Forest tram stop. No sign of why the barriers are down, but it's most likely to be down for a tram (does that count?)
http://goo.gl/maps/1LrFp - Zoomed-in version of the same barriers from the other side.
http://goo.gl/maps/QcB6g - Same side, different view, different time of day.
http://goo.gl/maps/upMjM Pedestrian LC just east of Nottm station (I think this used to be a through road). No train in this view, but if you move closer to it in Street View, a freight is revealed.
http://goo.gl/maps/Vm6Hr - LC on the busy Colwick Road in Nottingham.
Off to see the family now though, so will find more for you later
--- old post above --- --- new post below ---
Final few for tonight.
http://goo.gl/maps/CGfmQ - Crossing at Pencoed station, South Wales.
http://goo.gl/maps/sr2oi - And another.
http://goo.gl/maps/bJRQh - And another!
http://goo.gl/maps/5B1W3 - St George's LC (S. Wales Main Line) - west of Cardiff
http://goo.gl/maps/J51Op - St Fagan's LC, near Cardiff
http://goo.gl/maps/7mR3u - Ferryside station.
http://goo.gl/maps/r1g3V - Ferryside again, from the other side