Originally Posted by Helmet Head

It's a good explanation of the difference, by way of example, not definition.

I agree with Randya that "practical" is closer than "possible" to the meaning of "practicable", but more specifically practicable also conveys "reasonably safe" and "repeatable". So to me practicable means reasonably safe to repeatedly practice.

So a certain distance from the curb may be possible and even practical at the moment, but "as far right as practicable" may still be further left because it can't be done repeatedly like that.

Consider a road on which on street parallel parking is allowed. My interpretation of "as far right as practicable" is that you're not required to ride where cars can be parked just because they happen to not be there at that moment. It's not practicable to ride there, though it may be practical on that Sunday morning, because you can't ride there when cars are parked there.