When someone gives you directions like “Go west on Anderson Avenue until you hit the light, then turn and go up Smith Street until you see the red house”, which way is “up”-left, or right?
Up may be in the direction the house numbers get higher, or in the opposite direction from downtown. However, if you’re not familiar with the area, “up” could be utterly meaningless. If the person giving the directions didn’t specifically say left or right, I personally would be driving around in circles and possibly have to ask someone else for directions.
If there’s a hill?
I have a problem when someone asks me to turn up/down the AC.
Turn up/down the heat is easy, your move the thermostat up to a warmer temp and down to a cooler temp.
Does turn up the AC mean push the thermostat up to a higher temp, or push it down to a cooler temp?
To me going up the street is going to the right at an intersection. Going down is going to the left. That’s just me. I’m weirdly wired.
However, If someone has given me a number and I’m looking f or 2206 and I hit the intersection at the 2000 block and the numbers go up if I turn left, then going up the street means turning left.
Ascending numbers go up.
Those are just bad directions, it could mean either left or right. Even if there are ascending house numbers or a hill, someone who gives directions like that probably got them wrong anyway.
My guess would be up a hill, if present, or north if the street is flat.
Simpler to just ask the direction-giver to clarify. 
Up is the direction in which things don’t fall*
So if the directions tell you to go up, drop something and then travel in the opposite direction**
- Here on Earth anyway
** May be much easier if there is a hill, escalator, or elevator nearby.
Another place where these directions might make sense is Manhattan, where “uptown” and “downtown” mean toward higher- and lower-numbered streets.
I agree that such directions are bad. When telling someone how to get somewhere, why leave anything open to interpretation? “Left” and “right” have the same meanings to everyone.
For a viewpoint that I honestly already expected to see: “Up” is always north.
I think Manhattan is atypical in that the city started on the southern tip of a narrow island and developed from there. So uptown and downtown became synonymous with north and south.
Most cities have a more centralized “downtown” and develop out in several directions. So downtown could as easily be to the north as to the south.
From those directions I would have to assume that either:
[ul]
[li]the cross street is named differently in each direction, or[/li]
[li]Smith St. is one-way, or[/li]
[li]Smith St. begins at that intersection[/li][/ul]
Otherwise it’s completely ambiguous and bad directions.
“Up” means go forward. Those directions are ambiguous unless Smith St. is one-way.
Except he said to turn onto Smith street. Now if this were onto an avenue you’d have a point
(Yes, I *know *I’m nitpicking and fighting the hypothetical all at once. Deal 
:D)
This, plus another two possibilities, but in both these cases still not very good directions:[ul][]Smith st. is on a steep hill[]Ascending house numbers (this implies familiarity with the local numbering system however; if I’m asking it’s probably useless for me!)[/ul]
I think I say ‘up’ if it’s less than 2 blocks, ‘down’ if it’s 2 blocks or more. So I’m absolutely no help.
It doesn’t matter. The world is a globe. Turn either way, keep going long enough and you’ll arrive at your destination… eventually.
True dat.
That doesn’t help if the street runs east/west.
Or if you don’t know the area and have no way of telling which way is north.
To go “up” a street means to go with the ascending street numbers.
But you have to make the turn first to look at the numbers.