One other fundamental problem with salmoning which I didn't mention before is the inevitability of the car passing the bicycle or vice-versa. When a bike rides along with traffic, a following car can just stay behind the bike if it isn't safe or practical to pass. It may be slow, but at least both will make forward progress. But when the car and bike are riding toward each other, unless they both come to a complete stop, at least one must pass the other whether it is safe to do so or not. Whether there are cross streets or not or any of the other problems mentioned above, there is always that inherent issue.