U.S. Highway 6 (US 6) is an east–west United States Numbered Highway which runs across the U.S. state of Iowa. The route is signed in places as the Grand Army of the Republic Highway. Like all state highways in Iowa, it is maintained by the Iowa Department of Transportation (Iowa DOT). The route begins at the Missouri River crossing at Council Bluffs. From there, it travels east through Oakland and Atlantic. North of Atlantic, the highway overlaps Interstate 80 (I-80) until De Soto. Between De Soto and Adel, the highway overlaps US 169 before splitting off to the east toward Des Moines. Through the Des Moines area, the highway runs about north or south of the I-35/I-80 corridor.
At Altoona, the route again overlaps I-80 until Newton, where it splits away from I-80. The highway passes near or through the cities of Kellogg, Grinnell, Victor, Marengo, the Amana Colonies, and Tiffin before entering the Iowa City metropolitan area. Through Coralville and Iowa City, US 6 has no direct access to I-80, I-380, or US 218; other routes like Iowa Highway 1 (Iowa 1) and Iowa 965 provide direct access. From Iowa City, the highway heads to the east-southeast through West Liberty and Atalissa. Near Wilton, the route heads north to I-80 where it again overlaps to Davenport. At Davenport, US 6 then follows I-280 and US 61 before entering the city. On the eastern side of Davenport, it joins I-74 and enters Bettendorf before leaving Iowa for Illinois.
Dating back to 1910, the route US 6 follows was originally the Great White Way and River-to-River Road. Both were auto trails which connected Council Bluffs and Davenport. When the U.S. Numbered Highway System was created in 1926, the highway was designated U.S. Highway 32 (US 32). US 32 was renumbered in 1931 as US 6 was extended to the west coast. As the Interstate Highway System expanded in the 1950–1970s, US 6's importance as a cross-state route was diminished by I-80. As a result, the least-traveled sections of the route were moved onto I-80 and control of the vacated sections of highway was given to local jurisdictions.
Route description US 6 is a cross-state route that connects Council Bluffs and Davenport by way of Des Moines and Iowa City. The route parallels I-80 for most of its length; however, nearly one-third of the route overlaps the Interstate Highway. While the route is away from I-80, US 6 is a two-lane highway with a rural speed limit of . However, between Adel and Waukee, the roadway is a four-lane divided highway that has a speed limit of .
Western Iowa US 6 crosses the Missouri River via the Grenville Dodge Memorial Bridge, named after the Union Army general during the U.S. Civil War, into Council Bluffs with I-480. Just into the state, I-480 ends at an interchange with I-29. US 6 heads east along I-29 south on the western side of Council Bluffs, then it overlaps I-80 and continues due east. On the east side of Council Bluffs, I-80 and US 6 split. Near Oakland, the highway follows the north–south US 59 for . Near Lewis, the road turns to the north-northeast until it reaches Atlantic. In Atlantic, the route turns back to the east and heads toward downtown where it meets Iowa 83. US 6 / Iowa 83 travel together to the eastern side of Atlantic where they meet US 71. The three routes run together for , when US 6 / US 71 split away from Iowa 83 and continue north to I-80. At I-80, US 6 leaves US 71 and joins I-80. At this point, US 6 begins the first of three instances when its traffic is routed along I-80. In the eastern part of Cass County, the two routes meet the northern end of Iowa 148.
As I-80 and US 6 approach Adair, the highways curve slightly to the south to bypass the community. There are two interchanges in Adair; both of the intersecting roads, at one time or another, carried US 6. County Road G30 (CR G30), the White Pole Road, was the original alignment of US 6, while CR N54 has not carried US 6 since 1980. Further east is an interchange with Iowa 25. About south of the interchange is Freedom Rock. Each year for Memorial Day, the rock is repainted with a patriotic scene by local artist Ray "Bubba" Sorenson II. Near Dexter, I-80 and US 6 graze the northwestern corner of Madison County. After , the routes enter Dallas County and meet CR F60, another former alignment of US 6. Near the CR F90 / CR P58 interchange, they start heading northeast toward Des Moines. At De Soto, US 6 splits away from I-80 at the interchange with US 169.
Central Iowa At De Soto, US 6 turns to the north, overlapping US 169 for to Adel. East of Adel, US 6 is a four-lane divided highway for , during which it passes through Waukee, Clive, and Urbandale along Hickman Road and intersects I-35 / I-80. Over the next , it serves as the border between Urbandale and Windsor Heights. At 63rd Street in Des Moines, US 6 intersects Iowa 28. For , US 6 / Iowa 28 run together on Hickman Road. Turning north, they run together for another mile () along Merle Hay Road, named after the first Iowa service member in World War I. At Douglas Avenue, US 6 splits away from Iowa 28 and continues east, becoming Euclid Avenue just west of the Des Moines River. In north-central Des Moines, it intersects US 69 and I-235. In northeast Des Moines, it turns to the northeast along Hubbell Avenue, which takes US 6 to Altoona. West of Altoona, it intersects US 65 and continues northeast passing the Adventureland theme park and Prairie Meadows casino. In northwest Altoona, US 6 intersects I-80 and US 65. Here, US 6 rejoins I-80 for the second time. After a third exit for Altoona, the Interstate resumes its rural limit. Near Colfax, the highways cross the South Skunk River. After an interchange with Iowa 117, the highway is forced to the north to avoid crossing the river multiple times. As the roadway returns south to its original line, it meets CR F48, which was another former alignment of US 6.
At Newton, US 6 splits away from I-80 at the Iowa 14 interchange. US 6 overlaps Iowa 14 for . It turns off of Iowa 14 and enters the western side of Newton where it passes the Jasper County courthouse located in the downtown area. Between Newton and Grinnell, the route has more hills and curves. The highway crosses the North Skunk River near Kellogg. At Grinnell, it intersects Iowa 146 southwest of the Grinnell College campus. East of Grinnell, the route straightens out and is overlapped by US 63 for and by Iowa 21 for . Near Victor, US 6 takes a northeasterly course through Ladora toward Marengo. At Marengo, it intersects the eastern end of Iowa 212. east of Marengo is the western end of Iowa 20. Here, US 6 forms the southern leg of the Amana Colonies Trail. later, it is joined by US 151 for . US 6 heads to the southeast toward Tiffin and passes underneath I-380 but does not have direct access.
Eastern Iowa At Coralville, US 6 passes underneath I-80, but to the east, Coral Ridge Avenue provides direct access to I-80. Entering Iowa City, the highway passes the campus of the University of Iowa, its main hospital, and VA Hospital. US 6 curves to the south to be adjacent to the Iowa River, where it meets and overlaps Iowa 1 for . US 6 and Iowa 1 go in separate directions at a signal controlled intersection, where, less than away, US 6 crosses the Iowa River. From Iowa City, it heads in an east-southeast direction toward West Liberty. The highway enters West Liberty from the northwest corner and curves southward. At the northern end of Iowa 70, it turns to the east again toward Atalissa and Wilton. The road crosses the Cedar River southwest of Wilton. south of Wilton, the highway overlaps Iowa 38, and the two routes head toward I-80. At the Wilton interchange along I-80, Iowa 38 turns west and US 6 turns east onto the Interstate, respectively.
As I-80 and US 6 approach the Quad Cities metropolitan area, the speed limit drops again to . Just within the city limits of Davenport is the I-280 interchange. US 6 exits to the south to join I-280. US 61 also joins I-280 at this interchange but from the opposite direction. US 6 only overlaps I-280 / US 61 for before exiting onto Kimberly Road. Heading southeast into Davenport, US 6 is a two-lane highway for . At Fairmount Street, it becomes a four-lane divided highway and straightens out to head due east. Near NorthPark Mall, it intersects Northwest Boulevard, which becomes Iowa 130 at I-80, and both one-way legs, Welcome Way southbound and Brady Street northbound, of US 61 Business, which, prior to 2010, was US 61. US 6 briefly dips to the southeast and straightens out again toward I-74. The highway joins I-74 and heads to the south toward Moline, Illinois. For about , I-74 / US 6 forms the boundary of Davenport and Bettendorf. The two routes completely enter Bettendorf and descend into the Mississippi River valley, where they meet US 67 at a complex series of exit and entrance ramps. They then ascend the Iowa–Illinois Memorial Bridge, known locally as the I-74 Bridge, and cross the Mississippi River into Illinois.
History
Before the U.S. Numbered Highway System came into being in 1926, roads in Iowa were maintained and promoted by local organizations which sought to drive traffic into their communities. Two such organizations created virtually parallel routes connecting Council Bluffs and Davenport via Des Moines. The routes, the southern Great White Way and northern River-to-River Road, eventually merged into the Whiteway-7-Highway. The new route followed the Great White Way from Council Bluffs to Des Moines and the River-to-River Road from Des Moines to Davenport. In 1926, the Whiteway-7-Highway became US 32, which itself became US 6 in 1931. For a time, US 6 was the busiest highway in the state. After I-80 was built near US 6, portions of the U.S. Highway were moved onto the Interstate Highway. Interest in the original US 6 corridor has grown in the 21st century by people who seek to drive traffic back into their communities.
Great White Way/White Pole Road
The Great White Way was formed in 1910 by the White Pole Auto Club. The route was built along the Chicago, Rock Island and Pacific Railroad between Council Bluffs and Des Moines. Members of the auto club painted poles along the route white, which lead the route to be known as the White Pole Road. The Great White Way passed through Oakland, Atlantic, Adair, De Soto, and Valley Junction. In late 1912, the Great White Way was extended east to Davenport, passing through Pella, Oskaloosa, Washington, and Muscatine. In 1913, when the Iowa State Highway Commission began registering named trails longer than , the Great White Way Association paid the $5.00 fee (equivalent to $ in ) to become the first official registered highway route on July 30, 1914. When the primary highway system was created, the Great White Way was assigned Primary Road No. 2.
In 2002, a group of residents from Adair, Casey, Menlo, Stuart, and Dexter formed a new group to promote the White Pole Road. Their intention was to bring visitors to their towns by diverting some traffic from the nearby I-80 / US 6 corridor to the south and onto the historic road. Poles were painted white up to high line along the drive. White Pole Road logo signs in each town give a short history of the town and their founders.
River-to-River Road