Merging onto the highway question

Was wondering if anyone could offer me some tips on this subject. What would you do if you had to merge onto the highway, but there was no merge-lane to speed up in and you could only see incoming traffic as it comes around a bend?

I've found myself in this situation in the same spot trying to get onto the DC beltway from MD, and it's absolutely terrifying. I try to avoid it. Another question is what can you do if you can't match the speed of traffic? Let's say everyone's going 80, but you can only get up to about 50 before the merge lane ends or you have to go straight into the next exit. Do you stop and wait? This is a rare occurrence, but it happened to me once and due to heavy, crazy-fast traffic I couldn't find a gap and had to just go into the exit ahead and try to get back on the highway at a different point.