Length in Iowa: 322 miles/518 kilometers
Western terminus: Nebraska state line
(Missouri River) at Council Bluffs with I-480 (which ends ¾-mile into Iowa at the
interchange with I-29)
Eastern terminus: Illinois state line (Mississippi
River) at Bettendorf with I-74
Counties: Pottawattamie, Cass, Adair, Madison, Dallas, Polk,
Jasper, Poweshiek, Iowa, Johnson, Muscatine, Cedar, Scott
Cities along route: Council Bluffs, Oakland, Atlantic, Adair,
Stuart, Dexter, De Soto, Adel, Waukee, Clive, Urbandale, Windsor Heights, Des
Moines, Altoona, Newton, Oakland Acres, Grinnell, Ladora, Marengo, Tiffin,
Coralville, Iowa City, West Liberty, Atalissa, Wilton, Walcott, Davenport,
NHS: None on standalone segments
Freeway segments: None, aside from where it duplexes with I-80
or another interstate (see below)
Expressway segments: 12 miles between Adel and I-35/80
¾ miles with I-480, from the Nebraska state line to I-29 in Council Bluffs (westbound, they split immediately upon entering Nebraska)
5 miles with I-29, between I-480 and the southern split of I-29/80; this includes a 2½-mile triplex with I-80
With I-80 four times: 7 miles, between exits 1A and 8 in Council Bluffs (including the aforementioned triplex with I-29); 50 miles, between exit 60 in Cass County and exit 110 in Dallas County; 22 miles, between exit 142 in Altoona and exit 164 in Newton; and 19 miles, between exit 271 near Wilton to exit 290 in Davenport.
2½ miles with US 59 through Oakland
3½ miles with IA 83 east of Atlantic; this
includes a two-mile triplex with US 71.
8½ miles with US 71 between Atlantic and I-80
5 miles with US 169, between Adel and I-80 at De Soto
1½ miles with IA 28, between 63rd Street and Douglas
Avenue in Des Moines
1 mile with IA 14, from I-80 northward to the west edge of
2 miles with US 63 in northern Poweshiek County
4½ miles with IA 21 in eastern Poweshiek and western Iowa
counties near Victor
2 miles with US 151 west of Homestead
¾ miles with IA 1 in Iowa City
5 miles with IA 38 south of I-80
1 mile with I-280 and US 61 in Davenport, between I-80 and Exit 1
2½ miles with I-74, from exit 2 at the
Davenport/Bettendorf border into Illinois. (It continues for another 5 miles through Moline
before splitting at the I-74/I-280 junction near the Quad City Airport.)
Designated: December 1931, to the former US 32 across
Paving history: Most of US 6 was paved at the time of its designation except for the Raccoon River crossing
east of Adel; that segment was paved in 1932.
Major alignment changes:
November 18, 1935: New bridge across the Mississippi River between Bettendorf and
Moline, IL, opened (it previously crossed the Government Bridge between
Davenport and Rock Island). The second span opened November 23, 1959, with the bridge opening to four lanes of traffic on December 22, 1959.
July 28, 1955: Realigned between the western split with US 63 and Brooklyn (with US 63). The old alignment, which is now County Road F29, was used as a truck route for US 6 until the next segment opened.
October 25, 1956: Realigned between Brooklyn and a point east of Victor (bypassing Brooklyn and Victor) to straighten the road. The old alignment is now County Road F29, while IA 398 was designated from a piece of US 6 to serve Brooklyn.
November 4, 1958: Realigned along a new four-lane road and former county roads M and T south of Iowa City.
The old route followed Burlington Street and Muscatine Avenue; east of Iowa City it is now
County Road F46.
November 19, 1958: Switched routes with IA 90 (III) between
Dexter and I-35/80 at the Hickman Road interchange; US 6 was routed along I-35/80 between
the Grand Avenue interchange and Hickman Road.
September 5, 1960: Duplexed with I-80 between US 71 and present-day exit #100 near Dexter
after that segment opened; IA 90 (III) replaced its old route.
August 9, 1961: Duplexed with I-35 and I-80 between IA 90/Hickman Road and current exit #159
between Colfax and Newton. IA 90 (III) replaced its old route between these two points.
December 13, 1966: Duplexes eliminated; US 6 was realigned along former IA 90 (III) segments,
while IA 90 was given a piece of US 6 between I-80 and I-35.
December 3, 1968: Realigned east of downtown Council Bluffs (via Kanesville Boulevard) to allow for
an interchange with I-80; it previously followed McPherson Avenue and present-day County
September 2, 1971: Moved from Kimberly Road onto I-74 in Bettendorf after a new segment of I-74 was completed.
January 1, 1973: Duplexed with I-80 (again) between exit #60 and exit #76; the
old segments became part of IA 83 (west of Anita, after briefly becoming unsigned IA 973) and County Road G30.
1980: Duplexed with I-80 between exit #76 and exit #100 (removing US 6 from Guthrie County), between exit #142 in Altoona and exit #164 in Newton, and between exit #271 near Wilton and exit #290 in Davenport.
The old segment between Adair and exit #100 became IA 925,
the segment between Wilton and I-280 became IA 927, and the
segment between Altoona and Newton was briefly designated as IA 926 and is now signed as
County Road F48. (The legal descriptions were updated on April 28, 1981, and AASHTO approved all three relocations on June 25, 1981, but the changes had already taken effect by October 1980 per the 1981 state transportation map.)
July 1, 2003: Re-routed along I-80 between exit #100 and US 169 at exit #110, extending
the multiplex and also sharing US 169 from I-80 northward to Adel. The old segment became County Road F60.
December 2016: Rerouted along I-29 and I-80 between I-29 exit #53A and I-80 exit #8, after the city of Council Bluffs agreed to take over the segment along West Broadway for a major reconstruction project. The remaining segment along Kanesville Boulevard was designated as IA 906.
For maps of alignments in Council Bluffs, see Jeff Morrison's Council Bluffs/Omaha Highway Chronology page.
For other alignment changes in Davenport that are not listed here, see the Highways of Davenport and Bettendorf page.
For other alignment changes in the Des Moines area that are not listed here, see the Highways of Des Moines page.
For other alignment changes in the Iowa City area that are not listed here, see the Highways of Iowa City page.
October 21, 1966: Missouri River crossing was upgraded to a freeway when US 6 was moved onto the I-480 bridge.
November 22, 2000: Four-lane segment between Adel and I-35/80 opens
US 6 was extended westward from its western terminus in Erie, PA, to
Greeley, CO, by December 1931 — engulfing US 32 through Iowa and US 38, which ended in Omaha, along the way. A few years later it had extended all the way
to Long Beach, CA. (In 1964 it was truncated southwest of Bishop, CA.)
The US Route 6 Touring Association's home
page deals with the history of US 6; the association's Iowa chapter is here. "Historic Route 6" markers were first placed on the old segment between Wilton and I-280 after a dedication ceremony in Wilton on June 14, 2012, and the Association is in the process of marking the entire original US 6 route as such. Also, the White Pole Road Development Corporation has promoted the old US 6 segment between Adair and Dexter as a revival of the White Pole Road auto trail.
US 6's role as a major state corridor diminished with the construction
of I-80. Nonetheless, US 6 still carries a lot of local traffic, especially
in places like Davenport, Des Moines, and Iowa City. On August
4, 2002, the Des Moines Register ran a series of articles focusing on how
I-80's completion affected some towns along US 6.
US 6 is known as the Grand Army of the Republic Highway, a designation made
in 1947. Grand Army of the Republic signs are posted intermittently along the route, including on former US 6 segments that were moved onto I-80.
City US 6
Davenport and Bettendorf: This route was designated in early 1936 after the opening of the Iowa-Illinois Memorial Bridge (see the Highways of Davenport and Bettendorf page). Its original route was Main Street (south of Locust Street), 4th Street, Perry Street, and 2nd Street (according to the Davenport Democrat and Leader; the Highway Commission had it following 3rd Street instead). After the Kimberly Road bypass opened in December 1936, City 6 was extended westward along Locust Street and Hickory Grove Road. By 1941, according to the Quad Cities inset in the 1941 Illinois state highway map, City US 6 followed Hickory Grove Road (with IA 350), Locust Street, Brady Street (with US 61), 4th Street, and River Drive before ending at the US 6/67 junction in Bettendorf. It was realigned to follow Brady Street and River Drive, sharing the roads with US 61 and US 67, by 1955. It was gone by the early 1960s.
Des Moines: Designated after US 6 was shifted
to its present alignment along Merle Hay, Douglas, Euclid, and Hubbell Avenues on December 3, 1934. The route started at the intersection of Merle Hay and Hickman Roads, and then followed Hickman Road, Beaver Avenue, Forest Avenue, 19th Street, Keosauqua Way, 2nd Street, Grand Avenue, and Hubbell Avenue before joining mainline US 6 at the intersection of Euclid and Hubbell. It was on the official state highway map from 1964 to 1968 as a green line on the Des Moines inset map (labeled simply as "Business Route"). Maps produced by Gousha included it as late as 1976.