Ossulton Street / Euston Road intersection
The Ossulton Street / Euston Road intersection in NW1 sees a lot of traffic from cyclists commuting from north to central London. It's left-turn only for vehicle traffic, while a marked lane and a gap in the central island of Euston Road allow cyclists to cross the flow of traffic and turn right into Euston Road. The traffic lights ensure that traffic on Euston Road is stationary when the lights are green for cyclists coming from Ossulton Street. However, this often means that when the traffic is backed up on the eastbound lane of Euston Road, vehicles stop right in the path of cyclists trying to cross this lane in order to turn right.
Surely one solution would be to mark out the cycle lane here as a box junction, and make it an offence for cars to block it.