What does the one way sign mean?

You have turned onto a street where this sign is mounted at the corner. What does it tell you about the street?

Every vehicle on it travels in the direction of the arrow

A one-way street carries no oncoming traffic, so every lane on it, including the leftmost, is available to you. That also changes your turns, because a left turn here starts from the left lane instead of the centre of the road.

You want to turn onto a street where this sign is mounted with the arrow pointing to your left. What may you do?

Turn left only

The arrow shows the only direction traffic may travel on that street, so the only lawful way in is to turn the way the arrow points. Once you are on a one way street you may use whichever lane suits your next move, because there is no oncoming traffic to stay clear of.

What does this sign tell you about the road it faces?

Traffic on that road travels only in the direction of the arrow

A one way sign shows the only legal direction of travel on that road. Turning in against the arrow puts you head on into drivers who are watching for hazards ahead of them and have no reason to expect a vehicle coming the other way.

This sign is posted at the corner of a downtown street, where in Quebec you may also see the words SENS UNIQUE. You want to travel the other way along that street. What can you do?

Take a different street, since traffic here moves only in the direction of the arrow

SENS UNIQUE means one direction of travel, and the arrow shows which one. A quiet street changes nothing, because drivers pulling out of parking spaces and people crossing are all looking the single way traffic is meant to come from. Reversing the length of the street is the same mistake with worse visibility.

You are about to turn onto a downtown Winnipeg street that has this sign at the corner. What does the sign tell you?

Traffic on that street travels one way, the way the arrow points

A one-way sign shows the only direction traffic may travel on that roadway. Turn so you travel with the arrow; turning against it puts you head on with oncoming cars.

At a junction in downtown Sydney, this sign points right. Which direction may traffic follow on the signed street?

Right only

A one-way sign shows the only lawful direction of travel on that street. Follow the arrow rather than relying on how empty the road looks.