Blood on the streets

So, let's say they can apply for waivers for time-critical work, which would then allow TFL to put up signs alerting cyclists to the fact there will be HGVs along a route for a specific period of time and to avoid the area if possible and to be very wary of the heavy traffic if they can't.

Should cyclists not be alert all the time to the potential presence of HGVs?

Look around and you should be able to see the damned things.