Roadguy is not a fashion columnist, yet alert reader Mike has a question about hats:

At the 35W bridge construction site, I have noticed several distinct hardhat colors (yellow, orange, green, red, white, etc). I have been wondering if these hardhat colors have any specific meanings, or if it is completely random, and up to the worker's favorite color.

Roadguy is always given a green hat to wear when he's down at the site, and Kevin Gutknecht, a Minnesota Department of Transportation spokesman, says there is in fact something of a code.

Green hats are given to new workers or visitors; after 90 days, the workers get red ones. Supervisors from Flatiron Constructors tend to wear white hats, while the Figg Engineering folks lean toward blue and MnDOT prefers orange.

There are exceptions and variations, of course. And Gutknecht said a yellow hat could belong to a subcontractor or an inspector. (Or perhaps it just matches the wearer's socks.)

Left exit or right?

Alert reader LeRoy has a question about freeway signs that say things like "Hemlock Lane -- 1 mile."

In many states, LeRoy says, the little part of the sign showing the exit number will be attached on the right side of the sign if the exit is on the right, and attached on the left if the exit is on the left.

"One state that does not do this is Minnesota," he writes. "Why not?"

Federal guidelines call for the exit plaque, as it's sometimes called, to correspond to the side of the freeway that the ramp will be on, said Heather Lott, a MnDOT signage maven. Minnesota hasn't always done it that way -- they're often in the center -- but is in the process of moving the panels, she said.

Another road vanishes in the mist

After last week's item on the disappearance of Hwy. 65 from downtown Minneapolis, a few alert readers noted that Hwy. 55 also has departed.

Indeed. When sections of state highways no longer serve as real trunk routes, they're often turned over to cities or counties. (And, really, who from Eagan would take Hwy. 55 all the way to Plymouth when Interstate 494 is speedier?)

So Hwy. 55 is now in two parts: Olson Highway and points west, and Hiawatha Avenue and points southeast.

On the Olson end, there are a few signs directing Hwy. 55 traffic onto I-94, but if you're heading north on Hiawatha, there's nothing similar -- 55 just evaporates. Lott says there isn't room for more signs at that spot, where Hiawatha splits into a tangle of roads.

Jim Foti can be reached at 612-673-4491 or roadguy@startribune.com