Having taken Uber several times from home to downtown SF (and back) - anywhere from a 1-2 hr ride (depending on traffic) my most recent Uber driver said that they can set their app to only take rides that go in a particular direction.

So in my case, he headed up north for 2 hrs (7am morning peak hour rush). He said his next ride was a surge pricing and went to SFO (that's south of downtown SF for those that aren't familiar with NorCal geography). Then 2 more rides that eventually took him close to his starting point.

Got the above info by "pre-booking" him (pre-arranged for him to pick me up again at 7am the next morning). We had a nice chat on the way up to the city the next day as I was curious as to how the "direction setting" was working for him.

He also said that he makes more $$ by moving so a longer ride is always preferable to sitting and waiting for the next fare.

That being said I always call the driver as soon as they accept the ride to ask if they want to drive 2 hrs in peak traffic to the city. I always offer to cancel if they don't want to go out of their comfort zone. I do the same when I leave SF - ask if they want to drive over an hour south outside of SF. I've never been asked to cancel yet.