Nope I don't mean a merging lane, I literally mean a side road where you have to give way to a main road but the safest thing to do is to speed up to 60-70kmph and merge into like if it was a highway. It's completely legal and most safe. In Europe the "give way" sign doesn't say anything about your speed, just that you can't cause others to speed down. Btw the same sign is used on freeway merging lanes, having to slow down as you imply would be extremely dangerous; the correct way is to use the merging lane to match speed with the lane you're merging into.

I'm talking about this place: https://goo.gl/maps/2JwZGyzLPGG2