US 30 extends from west to east across the central portion of Iowa, with much of the highway traveling through rolling farmland. Small towns dot the entire route, which connects the larger cities of
Denison,
Ames,
Marshalltown,
Cedar Rapids, and
Clinton. Between
Ogden and
Mount Vernon, significant portions of the highway have been upgraded to a four-lane freeway.
Western Iowa US 30 enters the western end of Iowa by crossing the Missouri River on the Blair Bridge, located east of the Nebraska town of the same name. Adjacent to the highway bridge is the Union Pacific Railroad's river crossing for the Overland Route. The highway runs roughly parallel to the rail line for its entire run across Iowa. For , traffic moves through the flat Missouri River bottoms, passing
DeSoto National Wildlife Refuge on the way to
Missouri Valley. At Missouri Valley, it intersects
Interstate 29 (I-29) at a
partial cloverleaf interchange. It enters the
Boyer River valley through the
Loess Hills, a region of
wind-deposited silt extending from north of
Sioux City to extreme northwestern
Missouri. The rolling Loess Hills rise above the roadway while the land in the valley stays relatively flat. US 30 enters
Logan and intersects the eastern end of
Iowa Highway 127 (Iowa 127). The highway runs parallel to the Boyer River as well as the Overland Route in a general northeast direction from Logan. east of Logan is the western end of
Iowa 44, which extends east to Des Moines. The highway enters Crawford County north of
Dunlap in Harrison County. For , US 30 passes through farmland and the small communities of
Dow City and
Arion. For through Denison, it overlaps
US 59 and
Iowa 141, which
run concurrently through the town. The Iowa DOT refers to routes which overlap other routes as duplicate routes. It follows the East Boyer River through Denison as the Boyer River forks west of the northern intersection with US 59 / Iowa 141. US 30 travels north-northeasterly towards
Vail. Between Vail and
Westside, the highway ceases following the East Boyer River and heads due east towards
Arcadia and Carroll in Carroll County. At Carroll it intersects
US 71 on the western side of the city. Continuing east, the highway goes through the town of
Glidden and passes to the north of
Ralston, west of the Greene County line. North of
Scranton it meets the northern end of
Iowa 25. Between Scranton and
Jefferson, US 30 crosses the
Raccoon River. US 30 crosses
Iowa 4 and
Iowa 144 on the northern edge of Jefferson and
Grand Junction, the latter of the cities named for its location at the junction of the historic
Chicago & Northwestern and
Chicago, Rock Island and Pacific Railroads, now both owned by
Union Pacific, respectively. East of Grand Junction, the highway passes over the Overland Route where it stays south of the railroad until
Le Grand.
Central Iowa west of Ogden, US 30 is joined by
US 169 from the north. The two highways run concurrently until reaching Ogden, where the road becomes a four-lane expressway. US 169 exits to the south at a partial cloverleaf interchange, while US 30 continues east through Boone County and descends into the
Des Moines River valley. It ascends from the valley and travels another to a
four-way stop in Boone, which is the last stop along the route until Iowa 1 in Mt. Vernon, though this is now a roundabout. east of Boone, it meets
Iowa 17 at a diamond interchange. east of that interchange is a shortcut to northbound Iowa 17. Traffic is filtered into Ames and
Iowa State University (ISU) from US 30 through five interchanges. On the outskirts of Ames are the Lincoln Way interchanges, access to and from Lincoln Way is handled by two half interchanges apart. From the interchanges to the Story County line away, Lincoln Way is designated as
Iowa 930, but is never signed as such. The South Dakota Avenue interchange primarily serves the southwestern part of Ames. The University Boulevard (formerly Elwood Drive) exit provides access to the Iowa State University campus and
Iowa State Center, ISU's cultural and athletics complex. The Duff Avenue interchange provides access to Ames's east side.
US 69 and
Interstate 35 Business Loop are designated along Duff Avenue. From Duff to
I-35, US 30 is overlapped by the I-35 Business Loop. Between the Duff and Dayton Avenue interchanges, it crosses the
South Skunk River. The Dayton Avenue interchange serves hotels and restaurants and is a travel stop for I-35 travelers. East of the Dayton Avenue interchange is I-35, which connects US 30 to
Minneapolis, Minnesota, to the north, and
Des Moines to the south. Continuing east, the expressway travels to Nevada, more to the
US 65 interchange at Colo, to
State Center, and the Iowa 330 interchange on the western edge of
Marshalltown. to the east are two half-interchanges with
U.S. Route 30 Business (US 30 Business). US 30 bypasses Marshalltown approximately south of its business loop. Near
Marshalltown Community College, it intersects
Iowa 14 at a diamond interchange. The 18th Avenue interchange on the southeastern side of Marshalltown is the eastern end of the business loop. From Marshalltown, it travels to Le Grand, crossing over the Overland Route rail corridor on the west side. It bypasses Le Grand to the north, where it intersects the northern end of
Iowa 146 at a diamond interchange. Continuing east, the highway enters Tama County. It rises over a large hill north of
Montour and then descends into the
Iowa River valley. East of the Iowa River is the
Meskwaki Settlement, which is home to about 800
Meskwaki Native American tribespeople and the
Meskwaki Casino and Resort. As it heads into the Tama–Toledo area, the expressway bisects the two communities. Between the two cities, it meets
US 63 at a partial cloverleaf interchange. From US 63 it turns to the southeast to skirt Tama's east side. It rejoins the former alignment of the highway east of Tama and heads due east, along section lines in Tama and Benton Counties, and does not enter another town for .
Eastern Iowa US 30 enters Benton County north of
Belle Plaine at an intersection with
Iowa 21. It continues east along a
section line, passing the communities of
Keystone,
Van Horne, and
Blairstown. southwest of
Newhall, or southeast of Van Horne, it meets
US 218 and becomes a four-lane road. US 30 and US 218 travel together due east towards Cedar Rapids, passing
Norway and
Atkins. On the western end of Cedar Rapids, US 30 / US 218 turn to the southeast at the 16th Avenue SW interchange. to the southeast is the
Williams Boulevard interchange, where
US 151 joins US 30 and US 218. For , US 30 / US 151 / US 218 is a
wrong-way concurrency; that is, where two or more routes heading in opposite directions share the same highway. In this instance, US 30 is the main east–west road while US 151 and US 218 are duplicate routes, nominally heading north and south, respectively. At the
I-380 interchange, US 218 leaves US 30 / US 151 and joins the
Avenue of the Saints highway. East of I-380, US 30 / US 151 serve as a divider between the Lincolnway Village neighborhood to the south and a light industrial district to the north. South of
Bertram, the two routes cross the
Cedar River before US 151 splits away from US 30 to the north at a
trumpet interchange. This interchange is the southern end of
Iowa 13. The road dips southeast, ultimately bypassing the cities of Mount Vernon and
Lisbon, while converging back into a 2-lane road at the conclusion of the bypass. Over the next , US 30 passes through a small town every . In Cedar County it passes through
Mechanicsville,
Stanwood,
Clarence and
Lowden. In Stanwood, it is overlapped by
Iowa 38 for . In Clinton County, it passes through
Wheatland,
Calamus, and
Grand Mound before reaching a full
cloverleaf interchange with
US 61 at DeWitt. US 30 overlaps US 61 for , crossing the Union Pacific Overland Route in the process, and leaves US 61 via a trumpet interchange. US 30 continues east as an expressway, passing DeWitt to the south. east of DeWitt, it crosses back over to the north side of the Overland Route. West of the Clinton city limits is an interchange with Clinton County Road Z36 (CR Z36), which serves
Low Moor and as a shortcut to southbound
US 67. East of CR Z36, it passes the
Clinton Municipal Airport and a large chemical plant. As it approaches Mill Creek Parkway, it descends over in elevation into the flat Mississippi River valley, where it meets US 67. US 30 / US 67 head east along Lincoln Way and ascend onto a plateau, atop which reside stores and restaurants. As they continue east, the two routes split into one-way streets, eastbound Liberty Avenue and westbound Camanche Avenue. The one-way street alignment ends at 11th Avenue South, but quickly begins again as US 30 / US 67 turn to the north onto northbound South Third Street and southbound South Fourth Street. At Eighth Avenue South, US 30 splits away from US 67 and onto the
Gateway Bridge and crosses into
Illinois. ==History==