Cars flashing me at night

Well, then you're passing or letting traffic merge, which fits into that.

Also, of course, if you're in a country that drives on the left side of the road/right side of the car, flip the rule to keep left except to pass.

 

Can you still pass on either side in the US ?

 

I think it's usually legal, but if it's illegal, it happens a lot.

Also, enforcement of "keep right except to pass" is rare, and in some areas, signage says "through traffic keep left".

 

Yeah, that's never enforced at all. I hate when people get in the fast lane and hang out while people are passing them on the right. GTFO.

 

That may well vary by state. In both states where I have been licensed, it is legal as long as the passer uses a separate marked lane. Passing in the same lane or on the shoulder is illegal. I did see it enforced numerous times at one particular hazardous intersection, which has since been upgraded to have a separate turn lane.

 

City streets and highways are different.

Pass in any lane in the city. Pass on the left on the highway.

Apparently a lot of states have not had laws that specified the "keep right except to pass" rule and lately several of them have fixed that problem.