Northwest Incongruity

Dave Oosterhuis contributes this sign pair from Davenport, Iowa. It seems to be a fairly common practice for a math loving city to put multiple road signs on the freeways that show similar mathematical relationships (see Welcome To Omaha! and Welcome To Albuquerque). Davenport joins in the fun but adds a little sprinkle of intrigue at the same time! See if you can find it.

''These signs both take advantage of the somewhat controversial rule #4 that allows you to not use the numbers in the freeway designators because this is a mileage sign. This rule is currently under review and may change in the future.''



Hard to miss the math on the right side. Basic, simple addition.

$$2 + 4 = 6$$



Same to be said for this sign, again, basic addition.

$$2 + 5 = 7$$

So did you see the intrigue? The sign on top indicates the distance from Northwest Blvd to Brady St as 2 miles, and the second sign shows it as 3 miles. It's possible this is simply a mistake, or a bias in how rounding occurs to get to nice, round integers. However, it's also possible that Iowa has perfected some sort of flux capacitor that makes the distance actually shorter one way. Alternatively, perhaps after thousands of years of eating spice Iowans are now able to bend roads, that is to go from Northwest Blvd to Brady St without moving.

These signs were found on I-80 north of Davenport, Iowa. The first sign is found eastbound and the second sign is found westbound.

Ed.: This is the 70th winner on Road Sign Math and ties Iowa for the 2nd position in the state competition with 7 signs each!