Ask The Answer Person: Why are semis driving through downtown Decorah?

Posted: Wed, Feb 19, 2020 11:24 AM

PHOTO: The driver of this semi which knocked over a traffic signal on Water Street was never found.

(The Answer Person has been looking into the question of why many semis are driving through downtown Decorah and, in some cases, knocking over traffic lights):

Five times since last fall, a semi has knocked over a traffic light on Water Street. The working theory in Decorah is that semis are now driving through downtown because somehow the GPS information about Highway 9 has changed.

That theory seems to be supported anecdotally—one of the semi drivers who knocked over a traffic light told police he hadn't wanted to drive downtown, but that's where his GPS had sent him. State highway workers have said new signage went up on Highway 9 at the Pleasant Avenue bridge just about the same time the semis started traveling through downtown.

So the question now is, 'How can the GPS information be changed to take into account that, while the right lanes of Highway 9 at Pleasant Avenue have a height restriction, the left (middle) lanes of Highway 9 are NOT too low for semi traffic?'

The Answer Person has gone to the government website that's a clearing house for GPS information, www.gps.gov , and entered the revised information. But other highway officials say these commercial vehicle drivers probably are using navigation provided by their in-cab fleet info provider.

So Google Maps and Mapquest might not be sending semis through downtown Decorah—but that won't necessarily mean semis will stop knocking over traffic lights on Water Street until all GPS systems can be reprogrammed. That process could take a long time.