If the start of my journey is on a busy road, and there is a pedestrian crossing nearby, I often take advantage of the pedestrian phase of the crossing by mounting the bike, joining the carriageway and setting off while the lights are red for traffic already on the carriageway. (Making sure, of course, to take care of pedestrians and other users of the crossing.) This seems to me a safe and convenient way to join a busy road.
Is this common practice? Is it advisable? Is it Legal? I don't consider it "running a red" as I'm already over the stop line by the time I mount my bike, but I could see how it could be construed that way.
Likewise if I'm fortunate enough to "catch a red light" at a pedestrian crossing near the end of my journey, I might take the opportunity to dismount and enter the crossing from the carriageway, cross to the footway and finish my journey as a pedestrian. Is this also advisable/safe/legal? In this case I am crossing the stop line under a red light, albeit "as a pedestrian".
If it makes a difference to any of the legalities, I live in the UK - Scotland to be precise.