
Six years after the realignment of U.S. 61 to bypass Davenport, signs along U.S. 6 still reflect the U.S. 61 mainline instead of the business route.
Bill has previously located this set of mast arms along Central Park Avenue in Davenport. The assembly supports a variation of the Kentucky style of signals where the red and green lens use tunnel visors and the amber lens use cutout visors. The 12″ x 8″ x 12″ signal array is somewhat unique to us.
4th Street represents an early alignment of U.S. 61 from Main Street west to Pine Street.
During the 1940s, Iowa 22 between the Quad Cities and Muscatine was the original alignment of U.S. 61. Then Iowa 22 traveled what is now U.S. 61, or along the modern expressway that the US route takes to the north.
The Beckey Bridge opened to traffic on December 2, 1972. Iowa 92 lowers from the bridge to combine with U.S. 61 Business and Iowa 38 north along 2nd Street. The route previously turned south through Downtown, but that changed in September 2014 when maintenance of the route was turned over to the city of Muscatine.
U.S. 61 Business was designated in Muscatine in 1984 when the bypass to the north opened. Iowa 22 and 92 follow the bypass west.
Widening is underway along a six mile stretch of U.S. 61 from the Muscatine County line to Turkey Run. The US highway is being upgraded to a controlled access highway with interchanges planned at the south split with Iowa 92 and at 170th Street.
U.S. 34 and U.S. 61 cross paths at a parclo interchange in Burlington. The east-west route travels along a freeway between West Burlington and Gulf Port, Illinois. The freeway opened from U.S. 61 west in 1976.

Looking at the US 34 bridge from a riverside park and boat ramp on the Burlington side of the river.
Resuming a southward heading, we followed U.S. 61 to Lee County and the 2011-opened Fort Madison bypass. The 9.5 mile freeway sees three exits with County Roads, all using yellow back plates versus the standard white back plates you typically find across the state of Iowa.
We doubled back north on a more familiar road to all three of us, U.S. 218. Otherwise known as the Avenue of the Saints or Iowa 27, the expressway / freeway grade road provides a high speed route from the Keokuk area at the southeastern corner of the state north to Interstates 80 and 380 at Iowa City.
Throughout most of Washington County, we noted new larger signs posted for U.S. 218 & Iowa 27. Bill inquired with IowaDOT about this and was told the new installs went up approximately March 10th. Adhering to AASHTO standards, the signs measure at least 24 inches with the new reflectivity on them. New signs will be going on all route shields across the state for all highways (two and four lane) as needed after annual inspections of the signs.
We turned east from the Avenue of the Saints (I-380) along U.S. 30 to Mt. Vernon, Stanwood and Lowden. U.S. 151 currently travels along side U.S. 30 through to the Betram area. Our long time friend and contributor Chris recently mentioned that once the Iowa 100 expressway is completed along the west side of Cedar Rapids, that U.S. 151 will be realigned onto it.1

A roundabout joins US 30 and Iowa 1. This is the second roundabout along the route through Mt. Vernon. Both were added by October 2013.
Main Street is the former alignment of U.S. 61. The route was approved as a Business Route for U.S. 61 in 1998, but signs were never erected outside of this cutout and another (since removed).
Sources:
http://www.corridormpo.com/component/content/article/100-special-projects/180-highway-100-corridor-management-plan