Despite being of a certain age, I find crossing Surawong quite easy. You just wait for a small gap, and off you go. You can even wait in the middle. I find that the traffic is pretty forgiving. There are indeed a couple of marked crossing by Patpong, which make it slightly easier, if necessary. I also find it helpful to cross at the same time as a local, traffic even less likely to run you down! During the height of the rush hour traffic can be stationary, though, as mentioned, watch out for motorbikes.