If you've lived in Minneapolis for more than a little while, you're probably aware that if you're driving north on Cedar Avenue, hanging a left just before you reach Washington Avenue and following the arrow that says "To Third Street" affords speedy access to westbound I-94 and southbound I-35W (and, for that matter, to the new Hiawatha Avenue speedway). The question for today is: Why does the sign refer only to Third Street, and not to the freeways? After all, only a few blocks south on Cedar, the on-ramp to eastbound I-94 is clearly labeled. Numerous phone calls to the Minnesota Department of Transportation and the Minneapolis Office of Public Works failed to yield a satisfactory answer. ("I don't know," said one spokesman. "Someone must have decided not to mark it.") Everyone we talked to, however, noted helpfully that if you go up two blocks to Washington, you'll see the signs directing you to I-35W. Hmmm. We'll let the out-of-towners do that.