As you can see, getting stuck in a traffic jam (towards the end) would be really frustrating, especially if you're a bit afraid and just want to keep moving to keep the fear from building up. When I went, I was really worried about crowds and there were some, but it was totally worth pushing past them!
Just look at all you'll get to overcome. Just know that if you do have a fear of heights, this probably isn't the hike you should do to confront those. It's a dangerous hike if you're not prepared for what you're going to encounter.