Polk County to post temporary 25 mph speed zone after Falls City Black Rock Road work; formal study required

Polk County Board of Commissioners on Jan. 14 heard that a large pothole on Davidson Road was patched and that the Falls City Black Rock Road reconstruction is nearly complete, prompting county staff to post a temporary 25 mph speed zone on the county portion and to conduct a formal speed study within 180 days after construction.

The county’s Public Works Director told commissioners that crews applied a temporary patch to a pothole on Davidson Road that he estimated was “a 4 foot, something like that,” and that an emergency closure planned earlier was avoided. He said the Falls City Black Rock Road project is “pretty well wrapped up” and that the county will establish a temporary speed zone on the county portion because state statute allows posting based on changed roadway character during construction.

The Public Works Director said the county will post 25 mph on its portion of the project and then perform a formal speed investigation within 180 days after completion. “We will identify a speed that we think is safe, and … we have to do a formal speed investigation within a 180 days,” he said. The director added that the county must coordinate with the city for signage and that the city portion already has 25 mph signs in place.

Commissioners noted resident concerns about higher speeds on the city side near Bridge Street, particularly near an apartment complex, and the director said those concerns are part of the reason for the upcoming study. He referenced previous temporary postings on Rob Mill and Mistletoe roads as similar examples.

The director also described two remaining construction items: striping and right-of-way fencing. He said striping was delayed by weather and that crews are attempting to apply a different striping product that FHWA guidance allows for lower temperatures and higher humidity; he urged completion if a suitable weather window appears. On the fencing issue, the director said a waiver of remonstrance signed by a property owner resolved the right-of-way fence dispute and that the waiver was filed “a week or 2 ago.”

There were no substantive public comments on these items during the meeting. The board approved the meeting agenda and the minutes from its Jan. 7 meeting by voice vote; both motions passed unanimously as recorded in the transcript.

County staff said they will post county signage on the county-maintained segment and return with study results or recommendations if the formal speed investigation supports a different posted limit.