I had to laugh at your explanation, dxb....it was written seriously, but it tickled my funny bone! Especially the part about Spock's logic!

Once you explained what tighening up means when entering or leaving the motorway, I knew exactly what you meant. As Faldage said, our slip roads are called on and off ramps here in the states, and when I encounter a "short" off ramp, I am indeed in trouble, as I tend to exit the highway much faster than I should!

And I also know what you mean by the One Way Systems, where one way roads are sometimes a block apart. You are right....no one would get home without the counterpart a block away! We have them here in the states, usually in the older parts of cities, as you mentioned. I know there are many on the east coast, and also many as far southwest as Texas.