You should be able to stop, on your side of the road in the distance you can see to be clear. A professional driver would know this.

I've been out on my motorbike today and was riding on a very winding minor road behind a 32 tonne, 4 axle tipper. He came to a very slow crawl, and it was apparent that someone was on a pedal bike in front of him. He waited for a suitable place and gap in the traffic to pass and got past the bike without incident.