I'd be curious to know the difference between your experience and mine. U. S. here, and its rare that a motel turns me away. Now, there are several distinguishing characteristics of my travel. First, mostly by motorcycle, and second is that because I'm on the bike I'm probably in some out-of-the-way place and not downtown SF. My mode of travel is important, I think, because sometimes I think they feel sorry for me (especially when my wife's with me). Who wants to turn away a biker when it's 10C and pissing rain? (Never mind that I'm perfectly content to put my tent up if I don't find a room.)
Anyway, I'll bet I'm turned away from ad hoc hotel stops 10% of the time at most.
>(Never mind that I'm perfectly content to put my tent up if I don't find a room.)
Just curious: where exactly do you pitch a tent in a situation like that? It doesn't seem like it's that easy to find some open ground where some cop won't harass you for trespassing or something.
There are several phone apps that will tell you where the campgrounds are. Personally, I've never tried to camp where I'm not allowed (I don't count sleeping on a picnic table at a rest stop). One can often (usually?) find a campground either actually in town, or a few miles down the road. To my knowledge, I've never been turned away with a tent; there's always a 10x10' spot of grass to rent me.
Alternatively, if you're in a U. S. National Forest and can find a spot off the road, you can camp anywhere you want. It's how we do the majority of our camping in our VW Westfalia, where in Washington there are a plethora of spots 90 minutes from our house (no, I'm not telling <g>).
But that's for my mode of travel, which is usually off the beaten path. If you're looking for a place to stay in SF during WWDC, my advice will do you no good. OTOH, I rode to a conference in San Diego, had some room trouble and found a campground smack in the middle of SD a few miles from the hotel. So, I dunno, there might even be a campground in SOMA I don't know about. :-) (EDIT: curiosity got me: there's one out by Candlestick Recreation Area, if you don't mind paying $89/night!)
Same. I do multi day trips up and down both coasts as well as cross country trips. I generally drive until I'm tired then let the gps find me a hotel along my route. I've never tried to book ahead and never had any problems with the drop in. If a place is full (rare) I drive another 20 minutes down my route and do that one. Easy peasy and I travel by car.
Anyway, I'll bet I'm turned away from ad hoc hotel stops 10% of the time at most.