Quite often when I am outgoing somewhere and I see a photographic opportunity there is nowhere to pull over and safely stop off the road. So I carry on a while and if I haven't gone too far past my objective when I find a wide enough shoulder to park off the road then I stop there and walk back. This, of course, gives me some much-needed exercise so it's not all bad.
This problem is not confined to secondary roads where there is usually no shoulder, the road dropping quite sharply off from the edge of the seal to the drainage ditch, but also on the main highways where the problem is different.
On secondary roads, there is not the traffic to contend with but since many have a lot of sharp turns it is not safe to try and stop and park until you get to a straighter section and then hope there is a farm entrance or a slightly wider patch to park.
On the main highways, there is to some extent the same problem but more often than not you are simply unable to slow down to find somewhere to stop because you are trapped in a fast-moving line of traffic.