US 20 in Iowa

US 20 in Iowa

US 20
Get started Sioux City
End dubuque
Length 305 mi
Length 491 km
NebraskaSioux City


2×2 divided highway


Sac City

Rockwell City


Fort Dodge



high view

Webster City





Iowa Falls


Steamboat Rock


Grundy Center



Cedar Falls West

Cedar Falls South


Waterloo South







Manchester West

Manchester East





US 20 is a US Highway in the US state of Iowa. The road forms an east-west route in the north of the state, paralleling Interstate 80 for a considerable distance. US 20 is an important east-west route, with the entire route being a 2×2 divided highway, with significant portions of it constructed as a full-fledged freeway. US 20 is a highway for 235 kilometers between Fort Dodge and Delaware. The entire route is 491 kilometers long.

  • Topschoolsoflaw: State overview and brief history of Iowa, including its geography and popular cities.

Travel directions

US 20 near Manchester.

The Julien Dubuque Bridge over the Mississippi River.

US 20 in Nebraska begins as a bypass of Sioux City, a border town. The bypass is also part of Interstate 129. Immediately after the bridge over the Missouri River, an interchange with Interstate 29 follows, after which US 20 and US 75 form the southeastern bypass. On the east side of Sioux City, US 20 exits and heads east.

US 20 then forms a route through central Iowa. This is a long section designed as a 2×2 divided highway, with a limited degree of unevenness. There are no built-up areas on the route. On the 175-kilometer stretch from Sioux City to Fort Dodge, there are only small towns near US 20, which runs through a monotonous agricultural area. US 20 intersects several north-south routes, such as US 59, US 71, and US 169.

US 20 passes just south of the regional town of Fort Dodge and crosses the Des Moines River. Just before Webster City, US 20 becomes a full-fledged freeway, from here all intersections are grade separated. In uninhabited areas a cloverleaf follows with Interstate 35. It then takes another 100 kilometers to reach the first place of size, the city of Waterloo. US 20 forms the southern bypass of Cedar Falls and Waterloo here, crossing the Cedar River. Here you also cross the US 63 and US 218. Just east of Waterloo, Interstate 380 exits south to Cedar Rapids.

US 20 is then another freeway for a distance of 70 kilometers to Delaware. To the east, US 20 is again a 2×2 divided highway with intersections and some grade separated connections. US 20 then leads through a flat agricultural area to the Driftless Area, a hillier area close to the Mississippi River. One then descends to the city of Dubuque. US 20 crosses US 61 in Dubuque, then crosses the Mississippi River via the Julien Dubuque Bridge and US 20 continues in Illinois to Rockford.

  • thembaprograms: Geography information of Iowa, including animals and plants. Also covers brief history and major cities of the state.


The first bridge over the Mississippi River at Dubuque was an 1868 truss bridge, where a new bridge was built in 1887. The current Julien Dubuque Bridge dates from 1943.

US 20 was created in 1926 and was already the main east-west route in northern Iowa at the time. At that time, the route was already better developed than the more northerly US 18. Later, the US 20 was completely expanded into a 2×2 divided highway, partly on a new route, sometimes at a considerable distance from the original US 20. The original route was via Iowa Falls and downtown Cedar Falls and along the north side of Waterloo. This changed in 1974 when US 20 was routed over the new freeway south of Cedar Falls and Waterloo.

The western part of the upgrade is mostly executed as a double-lane road with predominantly at-grade intersections. Due to the small number of major intersecting roads, US 20 has few places where through traffic must stop at traffic lights. The section through central Iowa is largely a freeway, covering a total distance of 217 kilometers from Webster City past Waterloo and Manchester to Delaware. This is the longest stretch of freeway in Iowa that is not an Interstate Highway. The easternmost part is a mix of at-grade and grade-separated intersections.

The first stretch to be widened to 2×2 lanes was at Moville in western state in 1958. A year later, a 2×2 lane opened at Dubuque in far eastern Iowa. IN 1964 the westernmost section between Sioux City and Moville had been widened to 2×2 lanes. During the 1960s, 1970s, and 1980s, long stretches of US 20 in central and eastern Iowa were upgraded to 2×2 lanes, much of it as a freeway. However, the construction speed dropped from the 1980s due to a lack of money and political priority. In 1996 a grade-separated part opened in Dubuque. After 2000, the pace was resumed with the expansion of US 20, so that by 2003 it had completely 2×2 lanes east of Fort Dodge.

Then there was another 150 miles of US 20 in western Iowa that was still a single-lane road. At the end of the 2000s, the pressure increased to widen this part in its entirety to 2×2 lanes. In December 2010, a four-lane section opened between Rockwell City and Moorland. On November 19, 2012, a 42-mile stretch of highway opened between Rockwell City and Early. In 2015, Iowa increased fuel taxes to fund more road projects and doubling the US 20 was the top priority. On October 5, 2018, 31 kilometers of 2×2 lanes opened between Early and Holstein. The entire project was completed on October 18, 2018, extending US 20’s entire length in Iowa with 2×2 lanes.

Traffic intensities

The US 20 is a quiet road. East of Sioux City, this drops from 9,200 vehicles to 1,520 vehicles per day. The highway section east of Fort Dodge handles a bit more traffic, some 7,500 to 12,000 vehicles. Between Waterloo and Dubuque, there are between 6,500 and 13,500 vehicles per day.

US 20 in Iowa

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