This discussion has been around a lot longer than the internet and VFTT . . . at least since I started hiking as a kid (more than 50 years ago -- not something I like to dwell on, but it does put things in some perspective). No doubt the discussion was going on well before that, too.
The “rule” that I’ve heard as long as I can remember is that uphill travelers have the right of way.
Darren did a nice job of explaining why that’s so, using the the case of mountain bikers to illustrate. The same “physics” applies to hikers as to bikers: It just takes more energy to get moving upslope from a standstill than it does to get moving downslope from a standstill.
Some of the commentary here has suggested that downhill travelers ought to have the right of way because they are “carrying a greater head of steam,” making it more difficult for them to stop. Of course it is inherently more difficult to stop when headed downhill, just as it is more difficult to start when headed uphill. But it also seems to me, the responsible traveler on a shared path moves under full control, which means -- includes -- being able to stop whenever necessary for the sake of one’s own safety or anyone else’s, or as a matter of courtesy.
So my sense is that if stopping while headed downhill becomes difficult to the point I can’t do it without some whoop-de-do, then I may be traveling too fast to have full control, and ought to consider slowing down.
In actual practice, it seems that uphill-downhill hikers usually work out the right-of-way business according to the circumstances of the particular moment and meeting. Pete Hickey covered this very nicely in saying, “I yield to anyone who looks like they need it.” Dave M also was very sage in observing, “. . .common sense, courtesy, and those of us who look for a chance to rest at any excuse will suffice to handle any situation that arises.”
My own practice tends in the direction of (my) yielding whenever it seems like a little break would be welcome, which is often, regardless of whether I’m ascending or descending.
Experience indicates the matter of who yields when groups are involved can be considerably more problematic than when individuals meet on the trail. And the larger the group(s) the greater the difficulty (angst?).
I was raised and have lived a lot of years as an adult believing in the notion that group rights and interests (and those of larger groups) do not necessarily trump those of the individual (or smaller groups). So my own inclination is to think that larger groups ought to make sure singles, couples or smaller groups have good opportunity to keep moving ahead when the parties meet.
This all can be resolved pretty well by each of us thinking about how our own behavior affects the other guy, and realizing that our behavior as individuals within a group can make a difference in the collective impact our party has on other hikers. Judgement informed by The Golden Rule really can make even awkward bottlenecks go with relative comfort for all concerned.
These discussion always are worthwhile. They give us reason to think about our own behavior out there.
G.