Do we have to use cycle lanes if they're there?

http://maps.google.co.uk/maps?f=q&source=s_q&hl=en&geocode=&q=stratford+london,+United+Kingdom&sll=51.479111,0.024033&sspn=0.015235,0.036821&g=Charlton+Rd,+Greenwich,+London+SE3,+United+Kingdom&ie=UTF8&ll=51.542819,-0.000274&spn=0.001902,0.004603&t=h&z=18&layer=c&cbll=51.542815,-0.00029&panoid=wu4M41H6meyy2-Hfl_hrOQ&cbp=12,352.8608849609645,,1,12.499999999999975

There's one in Stratford which appears out of nowhere on the pavement; behind a bus shelter. It goes for all of 20m, then stops.

To be fair on that one, it looks like there is new paving before it starts and going back along the road there are shared use facility signs and the start at the bike land opposite the junction with Service Road 1. Crap of the council to to properly reinstate it when they resurfaced the pavement though.