# U.S. Route 30 in Iowa

U.S. Highway 30 (US 30) is a major east–west U.S. Highway which spans 330 miles (530 km) across the state of Iowa. It is the longest primary highway in the state and is maintained by the Iowa Department of Transportation (Iowa DOT). The route in Iowa begins at the Missouri River crossing at Blair, Nebraska, and ends at the Mississippi River crossing at Clinton, Iowa. Along the way, it serves Denison and Carroll in western Iowa, Boone, Ames, and Marshalltown in central Iowa, and Tama, Cedar Rapids, and DeWitt in eastern Iowa. Cutting across the central portion of the state, US 30 runs within close proximity of the Union Pacific Railroad's Overland Route for its entire length.
US 30 was conceived as a part of the Lincoln Highway, the first transcontinental highway in the United States. A route through Iowa was chosen because of the important link between Omaha, Nebraska, and Chicago, Illinois. As the U.S. Highway System came into being in the 1920s, and the Lincoln Highway became US 30, federal money started to pay for paving Iowa's dirt roads. By 1931, the route had been paved across the entire state.
The route of the Lincoln Highway and US 30 has accommodated the changing needs of the traveling public. Early Lincoln Highway travelers were directed into many small towns as the route traveled 358 miles (576 km) across the state. Towards the middle of the 20th century, the route was straightened, bypassing most downtown areas and several towns altogether. More recently, long sections of US 30 have been upgraded to a four-lane expressway to accommodate increasing traffic. Since 2006, the highway has been designated an Iowa Heritage Byway by Iowa DOT, the first highway in the state with that distinction.

## Route description

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 nine miles (14 km), 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 50–100 feet (15–30 m) 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. Four miles (6.4 km) east of Logan is the western end of Iowa 44, which extends 105 miles (169 km) east to Des Moines.
The highway enters Crawford County north of Dunlap in Harrison County. For seventeen miles (27 km), US 30 passes through farmland and the small communities of Dow City and Arion. For one-half mile (800 m) 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

Four miles (6.4 km) 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 two miles (3.2 km) 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. Three miles (4.8 km) east of Boone, it meets Iowa 17 at a diamond interchange. One mile (1.6 km) 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 three-quarters mile (1.2 km) apart. From the interchanges to the Story County line one and three-quarters miles (2.8 km) 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 six and a half miles (10.5 km) to Nevada, six miles (9.7 km) more to the US 65 interchange at Colo, seven and a half miles (12.1 km) to State Center, and seven and a half miles (12.1 km) the Iowa 330 interchange on the western edge of Marshalltown. One mile (1.6 km) to the east are two half-interchanges with U.S. Route 30 Business (US 30 Business). US 30 bypasses Marshalltown approximately one-quarter mile (400 m) 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 five miles (8.0 km) 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 40 miles (64 km).

### Eastern Iowa

US 30 enters Benton County nine miles (14 km) 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. Three and a half miles (5.6 km) southwest of Newhall, or four and a quarter miles (6.8 km) 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. Two miles (3.2 km) to the southeast is the Williams Boulevard interchange, where US 151 joins US 30 and US 218. For four miles (6.4 km), 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 45 miles (72 km), US 30 passes through a small town every four to seven miles (6 to 11 km). In Cedar County it passes through Mechanicsville, Stanwood, Clarence and Lowden. In Stanwood, it is overlapped by Iowa 38 for one mile (1.6 km). 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 one mile (1.6 km), 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. Five miles (8 km) 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 100 feet (30 m) in elevation into the flat Mississippi River valley, where it meets US 67. US 30 / US 67 head east along Lincoln Way and ascend 50 feet (15 m) 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

The path which US 30 follows has changed since it was originally planned as the Lincoln Highway in the early 1910s. The first path connected as many downtown areas as possible, in order to create awareness about the Good Roads Movement and the Lincoln Highway. As the primary highway system of Iowa matured, and the Lincoln Highway yielded to US 30, the highway was gradually straightened, leaving many towns off the route. More recently, new construction has routed traffic away from the straighter roads and onto sections of freeway and expressway.

### Lincoln Highway

US 30 was created with the U.S. Highway System in 1926, but the route it takes dates back to 1913, when the Lincoln Highway Association (LHA) designated the route across the country. The brainchild of Carl Fisher, the Lincoln Highway was the first highway to cross the United States, connecting New York City to San Francisco. In Iowa, it was uncertain exactly where the Lincoln Highway would run. As of August 1913, no definite route had been planned; the only certainty was the route would pass through Iowa. Iowans raised over $5 million (equivalent to $113 million in 2023 dollars) for the construction of the road. On September 14, 1913, the Lincoln Highway Association announced the route. It was 358 miles (576 km) of dirt roads, connecting Clinton, DeWitt, Cedar Rapids, Tama, Marshalltown, Ames, Jefferson, Denison, Logan, and Council Bluffs. The route was marked by a red, white, and blue tricolor emblazoned with an L. The route markers were painted upon telephone poles, bridges, and nearby buildings to show travelers the way.
While not ideal for transcontinental travel, Iowa's dirt roads were of high quality. Foreigners even compared them to the best roads in France. However, the same could not be said when they were wet. The mud was so thick and viscous it was nicknamed "gumbo". To show travelers the obvious benefits of paved roads, the Lincoln Highway Association began the process of creating seedling miles of paved roads. The idea, according to Henry B. Joy, then-president of the Lincoln Highway Association, was to show travelers, for one mile (1.6 km), how fast and smooth their trip could be, only to bring them back to reality at the end of the mile. Seedling miles were placed at least six miles (9.7 km) from the nearest town and in areas where the terrain was rough. Between August 1918 and June 1919, Iowa's first seedling mile was built in Linn County, west of Mount Vernon. The ribbon of concrete, which was 16 feet (4.9 m) wide, 7+1⁄2 inches (19 cm) thick, and crowned for drainage 1+1⁄2 inches (3.8 cm), cost nearly $35,000 (equivalent to $460,000 in 2023 dollars) to build.
Despite the success of the seedling miles across the country, Iowa lagged behind other states in improving its roads. Before 1924, Iowa's 99 counties, not the state highway commission, were responsible for the construction and maintenance of the state's roads. In the 1920s, road paving cost $30,000 per mile ($19,000/km), equivalent to $681,000 per mile ($423,000/km) in 2023 dollars; a major obstacle for county boards of supervisors that wanted to pave their roads. When counties could afford to build roads, the Iowa State Highway Commission required extensive grading to be performed before paving could occur. In 1922, only five percent of Iowa's roads, 334 miles (538 km), were paved. By 1924, twenty percent of the Lincoln Highway in Iowa had been paved, and by 1931, it was paved continuously from New York City to Missouri Valley, Iowa.

### 1930s–1950s

When the Lincoln Highway became U.S. Highway 30 in 1926, the route was 358 miles (576 km) long and passed through every town along the way. Starting in the 1930s, the route's alignment began to be straightened. By the mid-1930s, it was routed west of Missouri Valley on old Iowa 130. The US 30 alignment south of Missouri Valley became U.S. Highway 30 Alternate. By 1952, it had moved south of Marshalltown and was replaced by Iowa 330 and a seventeen-mile (27 km) southern jaunt through Belle Plaine had been replaced by a straight road. In 1955, a couple of routing changes occurred. In Cedar Rapids, it began its move to the south, avoiding the downtown area, and in Clinton, it was rerouted over the Gateway Bridge, allowing Iowa 136 to cross the Lyons-Fulton Bridge. However, by 1957, the old alignment through Clinton and across the Lyons-Fulton Bridge was numbered U.S. Highway 30 Alternate.

### 1960s–1980s

In the 1960–1970s, Iowa DOT started to build freeway segments along US 30. In 1965, it was straightened and rerouted to the south of Ogden and Boone along an eleven-mile (18 km), four-lane stretch of road. By the end of the 1960s, both of the alternate routes had been turned over to local jurisdictions. The western route became Iowa 183, and the eastern route reverted to Iowa 136. By 1973, that new stretch of road had been extended fourteen miles (23 km) along a four-lane bypass around Ames. The old alignment became Iowa 930. In eastern Iowa, a new, twenty-mile-long (32 km) freeway connected DeWitt and Clinton by 1976. By 1985, the bypass of Cedar Rapids had been completed from 16th Avenue SW to Iowa 13 near Bertram. The bypass was extended five miles (8 km) further west in 1989. Between 1996 and 2000, an $8.2-million extension (equivalent to $14.7 million in 2023 dollars) was built to connect the bypass to the western intersection of US 218.
Since the Cedar Rapids bypass was completed in 1985, on occasion, traffic has had to be rerouted off of US 30. The bypass's proximity to the Union Pacific Railroad mainline resulted in an elevated roadway between Edgewood Road and Sixth Street SW. When strong winds come from the south, fog produced by an Archer Daniels Midland plant adjacent to the highway billows over the road making driving dangerous. The Iowa DOT set up an emergency detour from Edgewood Road SW north to 16th Avenue SW east to 6th Street SW back to US 30. The frequency of fog-related detours has decreased in recent years due to improved technology and the plant's expansion and relocation of cooling towers away from the highway.

### 1990s to the present

The 1990s saw more construction of four-lane roads along US 30. Stretches of four-lane roads that had already been constructed were extended towards other communities. In Story County, it was widened to four lanes from the I-35 interchange to US 65 at Colo. The original 1950s-era bypass of Marshalltown was itself bypassed in 1997 by a freeway three-quarters mile (1.2 km) south of the original bypass. That road, Iowa Avenue in Marshalltown, was designated as U.S. Route 30 Business, the first business route along US 30 in Iowa. The four-lane stretch southeast of Cedar Rapids was extended another five miles (8.0 km) to a point two miles (3.2 km) west of Mount Vernon, costing $5.6 million (equivalent to $10 million in 2023 dollars) to build.
Since the beginning of the 21st century, Iowa DOT has continued to widen US 30 to four lanes. In 2004, an $18.6-million (equivalent to $33.4 million in 2023 dollars), four-lane section opened from east of Marshalltown to the Meskwaki Settlement west of Tama, bypassing Le Grand. In 2010, two sections of expressway were completed. A seven-and-a-half-mile-long (12 km) section from Colo to State Center opened to westbound travelers on November 29, while the eastbound lanes opened a week later. The seven-and-a-half-mile-long (12 km) section, which bypasses the Tama/Toledo area, opened in two segments. The first of which opened on November 1, and the second on November 25. On July 7, 2011, a section from State Center to Iowa 330 opened in Marshall County. On November 22, 2019, an eight-mile (13 km) extension opened, bypassing Mt. Vernon and Lisbon. In June 2021, a nine-mile-long (14 km) segment opened in Tama County.

### Legacy of the Lincoln Highway

While the Lincoln Highway has not been an official route for 99 years, it is still a source of pride in the communities and regions through which it passed. Nearly 85 percent of the original Lincoln Highway is still drivable, although much is gravel. Most of what is drivable is either along US 30 or within one mile (1.6 km). The Lincoln Highway bridge in Tama was built in 1915. It was restored in the 1980s after local officials feared losing the then-deteriorating bridge. Preston's Service Station, a landmark of Belle Plaine, has become a Lincoln Highway museum. Monuments were built along the route to honor not only Abraham Lincoln, but to honor Iowans who were influential for planning its route.
In 1992, the Lincoln Highway Association was reformed with a chapter in each state through which the highway passed. The new LHA is a historical preservation group that wants to preserve the remaining sections of the highway. The Iowa chapter of the LHA has, since 2008, sponsored a tour of the Lincoln Highway. To keep friendly to classic cars, the tour does not travel upon the sections of the road which are gravel. After years of lobbying by the LHA, the Iowa Department of Transportation, in 2006, designated the Lincoln Highway the first Iowa Heritage Byway. The 2010 Transportation Map of Iowa showed the path designated as the Iowa Heritage Byway for the first time.

## Major intersections

| County | Location | mi | km | Exit | Destinations | Notes |
| Missouri River | Missouri River | 0.000 | 0.000 | | US 30 west / Lincoln Highway – Blair | Continuation into Nebraska |
| Blair Bridge; Nebraska–Iowa state line ||
| Harrison | Missouri Valley | 9.246 | 14.880 | | I-29 – Council Bluffs, Sioux City | I-29 exit 75 |
| Harrison | Missouri Valley | 10.617 | 17.086 | | N. 1st Street | Former Iowa 183, US 75 |
| Harrison | Missouri Valley | 10.978 | 17.667 | | Lincoln Highway Heritage Byway (S. 6th Street) | Former US 30, Iowa 183, and US 75 |
| Harrison | Logan | 19.291 | 31.046 | | Iowa 127 west – Magnolia, Mondamin | |
| Harrison | Jefferson Township | 23.178 | 37.301 | | Iowa 44 east – Portsmouth | |
| Harrison | Dunlap | 37.754 | 60.759 | | Iowa 37 east – Earling | Western end of Iowa 37 overlap |
| Harrison | Dunlap | 37.989 | 61.137 | | Iowa 37 west – Soldier | Eastern end of Iowa 37 overlap |
| Crawford | Denison | 51.145 | 82.310 | | US 59 south / Iowa 141 east – Harlan | Western end of US 59 / Iowa 141 overlap |
| Crawford | Denison | 54.547 | 87.785 | | US 59 north / Iowa 141 west to Iowa 39 – Ida Grove | Eastern end of US 59 / Iowa 141 overlap |
| Carroll | Arcadia | 72.723 | 117.036 | | CR M68 – Arcadia | Former Iowa 285 |
| Carroll | Carroll | 81.366 | 130.946 | | US 71 – Lake View, Audubon | |
| Carroll | Glidden | 89.449 | 143.954 | | CR N41 north / CR N44 south – Lanesboro, Lake City, Coon Rapids | Former Iowa 286 |
| Carroll | Glidden Township | 93.442 | 150.380 | | Lincoln Highway Heritage Byway east | Former US 30 |
| Greene | Ralston | 95.117 | 153.076 | | Lincoln Highway Heritage Byway | Former US 30 |
| Greene | Kendrick–Scranton township line | 99.237 | 159.706 | | Iowa 25 south / Lincoln Highway Heritage Byway – Scranton | Former US 30 |
| Greene | Jefferson | 108.198 | 174.128 | | Iowa 4 – Jefferson, Churdan | |
| Greene | Grand Junction | 115.242 | 185.464 | | Iowa 144 – Rippey, Paton | |
| Greene | Grand Junction | 117.003 | 188.298 | | Lincoln Highway Heritage Byway west / CR E53 | Former US 30 |
| Boone | Amaqua–Beaver township line | 122.260 | 196.758 | | US 169 north – Fort Dodge | Western end of US 169 overlap |
| Boone | Ogden | 125.294 | 201.641 | | Lincoln Highway Heritage Byway east – Ogden | Former US 30 |
| Boone | Ogden | 126.356 | 203.350 | 126 | US 169 south – Ogden, Adel | Eastern end of US 169 overlap |
| Boone | Boone | 134.009 | 215.667 | | CR R23 / Story Street | Former Iowa 164 |
| Boone | Des Moines–Worth township line | 137.316 | 220.989 | 137 | Iowa 17 – Madrid, Stanhope | |
| Boone | Colfax Township | 138.298 | 222.569 | | Lincoln Highway Heritage Byway west | Former US 30 |
| Boone | Colfax Township | 141.790– 142.688 | 228.189– 229.634 | 142 | Lincoln Way (Iowa 930) – Napier | |
| Story | Ames | 144.885 | 233.170 | 144 | CR R38 (South Dakota Avenue) – Kelley | |
| Story | Ames | 147.003 | 236.578 | 146 | University Boulevard – Iowa State University | |
| Story | Ames | 148.524 | 239.026 | 148 | I-35 Business Loop north / US 69 (Duff Avenue) – Huxley | Western end of I-35 Business overlap |
| Story | Ames | 149.745 | 240.991 | 150 | Dayton Avenue | |
| Story | Ames | 150.534 | 242.261 | 151 | I-35 / I-35 Business Loop ends – Des Moines, Minneapolis | I-35 exit 111; exits signed as 151A (south) and 151B (north); eastern end of I-35 Business overlap |
| Story | Grant Township | 152.034 | 244.675 | 153 | 580th Avenue | |
| Story | Nevada | 156.620 | 252.055 | | S. 6th Street | Former Iowa 133 |
| Story | Nevada | 157.595 | 253.625 | 157 | 19th Street – Nevada | |
| Story | Colo | 164.057 | 264.024 | 164 | US 65 – Des Moines, Iowa Falls | |
| Marshall | State Center | 171.479 | 275.969 | | Durham Avenue | Former Iowa 234 |
| Marshall | Washington Township | 179.938 | 289.582 | 179 | Iowa 330 – Albion, Melbourne, Des Moines | Des Moines only signed westbound |
| Marshall | Timber Creek Township | 180.641– 181.102 | 290.714– 291.455 | 181 | US 30 Bus. east (Iowa Avenue) | Eastbound exit and westbound entrance only |
| Marshall | Timber Creek Township | 182.023 | 292.938 | 182 | Oaks Avenue, Highland Acres Road | Westbound exit and eastbound entrance only |
| Marshall | Marshalltown | 184.531 | 296.974 | 185 | Iowa 14 – Newton, Marshalltown Business District | |
| Marshall | Marshalltown | 186.013 | 299.359 | 186 | US 30 Bus. west (18th Avenue) | US 30 Business signed westbound only |
| Marshall | Le Grand Township | 187.722 | 302.109 | | Lincoln Highway Heritage Byway west (Shady Oaks Road) | Former US 30 |
| Marshall | Le Grand | 191.182 | 307.678 | 192 | Iowa 146 south / Lincoln Highway Heritage Byway east / CR T37 north – Le Grand, Grinnell | |
| Marshall | Le Grand | 192.176 | 309.277 | | Main Street | Former US 30 |
| Tama | Indian Village Township | 194.125 | 312.414 | | CR T47 – Montour | Former Iowa 135 |
| Tama | Toledo Township | 199.950– 200.204 | 321.788– 322.197 | — | US 30 Bus. – Toledo | Westbound exit and eastbound entrance only |
| Tama | Toledo | 202.037 | 325.147 | 202 | US 63 – Tama, Toledo | |
| Tama | Tama Township | 204.223 | 328.665 | 204 | US 30 Bus. west / Lincoln Highway Heritage Byway – Tama | US 30 Business only signed eastbound |
| Tama | Otter Creek Township | 208.877 | 336.155 | | Lincoln Highway Heritage Byway east / CR E66 – Chelsea | Former US 30, Iowa 212 |
| Tama–Benton county line | York–Kane township line | 217.222 | 349.585 | 217 | Iowa 21 – Belle Plaine, Dysart | Interchange opened on August 30, 2023 |
| Benton | Kane Township | 220.037 | 354.115 | | Lincoln Highway Heritage Byway west / CR V40 – Belle Plaine | Former US 30, Iowa 131 |
| Benton | Kane Township | 222.046 | 357.348 | | CR V42 – Keystone | Former Iowa 200 |
| Benton | Union Township | 228.036 | 366.988 | | CR V66 – Van Horne, Blairstown | Former Iowa 82 |
| Benton | Eldorado Township | 231.004 | 371.765 | 231 | US 218 north – Vinton | Western end of US 218 overlap |
| Benton | Eldorado Township | 239.956 | 386.172 | | CR W14 – Newhall | Former Iowa 287 |
| Benton | Fremont Township | 237.000 | 381.415 | | CR W24 – Norway | Former Iowa 201 |
| Benton | Fremont Township | 239.985 | 386.218 | | CR W28 – Atkins | Former Iowa 279 |
| Linn | Clinton Township | 243.114– 244.504 | 391.254– 393.491 | 246 | Iowa 100 east – Cedar Rapids, Marion 80th Street SW to 16th Avenue SW – Fairfax | Eastbound signed exits 246A (Iowa 100) and 246B (80th Street SW); former US 30 |
| Linn | Cedar Rapids | 246.126 | 396.101 | 248 | US 151 south / US 151 Bus. north (Williams Boulevard SW) – Amana Colonies | Western end of US 151 overlap; former Iowa 149 |
| Linn | Cedar Rapids | 247.619 | 398.504 | 250 | Edgewood Road SW | |
| Linn | Cedar Rapids | 249.683 | 401.826 | 252A | 6th Street SW – Hawkeye Downs | Former US 218, US 30 |
| Linn | Cedar Rapids | 250.017 | 402.363 | 252 B–C | I-380 / US 218 south / Iowa 27 – Cedar Rapids, Iowa City, Airport | I-380 exit 16; eastern end of US 218 overlap |
| Linn | Cedar Rapids | 250.694 | 403.453 | 253 | Kirkwood Boulevard SW, Bowling Street SW | |
| Linn | Cedar Rapids | 251.693 | 405.061 | 254 | CR W6E (C Street SW) – Ely | Signed as exits 254A (south) and 254B (north) eastbound |
| Linn | Bertram Township | 256.630 | 413.006 | 259 | US 151 north / Iowa 13 north – Marion | Eastern end of US 151 overlap |
| Linn | Franklin Township | 261.199 | 420.359 | | Business 30 SW | Former US 30 |
| Linn | Mount Vernon | 262.668 | 422.723 | 265 | Iowa 1 – Mount Vernon, Solon, Cornell College, Historic Districts | Exit opened November 22, 2019 |
| Linn–Cedar county line | Franklin–Pioneer township line | 266.147 | 428.322 | 268 | Lisbon | Exit opened November 22, 2019 |
| Cedar | Stanwood | 277.743 | 446.984 | | Iowa 38 north (Ash Street) – Olin | Western end of Iowa 38 overlap |
| Cedar | Fremont–Dayton township line | 278.758 | 448.618 | | Iowa 38 south – Tipton | Eastern end of Iowa 38 overlap |
| Cedar | Clarence | 282.745 | 455.034 | | Lincoln Highway Heritage Byway east / CR X64 to Iowa 130 | Former US 30 |
| Cedar | Massillon Township | 287.121 | 462.076 | | Lincoln Highway Heritage Byway west | Former US 30 |
| Cedar | Massillon Township | 288.005 | 463.499 | | Lincoln Highway Heritage Byway east | Former US 30 |
| Clinton | Spring Rock Township | 297.105 | 478.144 | | Lincoln Highway Heritage Byway west | Former US 30 |
| Clinton | DeWitt | 308.348– 308.885 | 496.238– 497.102 | 311 | US 61 north – Maquoketa Lincoln Highway Heritage Byway east – DeWitt | Western end of US 61 overlap; former US 30 |
| Clinton | DeWitt | 309.759– 310.329 | 498.509– 499.426 | 312 | US 61 south – Davenport | Eastern end of US 61 overlap |
| Clinton | DeWitt | 311.772 | 501.748 | 313 | 6th Avenue – DeWitt | Former US 61, Iowa 956 |
| Clinton | De Witt–Eden township line | 316.368 | 509.145 | | Lincoln Highway Heritage Byway west / CR Z24 | Former US 30, Iowa 948 |
| Clinton | Eden–Camanche township line | 321.372 | 517.198 | 323 | CR Z36 – Low Moor, Elvira | Former Iowa 391 |
| Clinton | Clinton | 327.177 | 526.540 | | US 67 south / Great River Road (Washington Boulevard) – Camanche | Western end of US 67 overlap; US 67 is the Great River Road |
| Clinton | Clinton | 327.422 | 526.935 | | Lincoln Highway Heritage Byway (Harrison Drive) | Former US 30 |
| Clinton | Clinton | 330.164 | 531.347 | | US 30 west / US 67 south (S. 4th Street) | One-way couplet |
| Clinton | Clinton | 330.465 | 531.832 | | US 67 north / Great River Road (S. 3rd Street) / 8th Avenue South | Eastern end of US 67 overlap |
| Mississippi River | Mississippi River | 330.856 | 532.461 | | Gateway Bridge; Iowa–Illinois state line | Gateway Bridge; Iowa–Illinois state line |
| Mississippi River | Mississippi River | 330.856 | 532.461 | | US 30 east – Morrison | Continuation into Illinois |
| 1.000 mi = 1.609 km; 1.000 km = 0.621 mi Concurrency terminus Incomplete access |||||||