Interstate 35 (I-35) serves the central United States. As with most interstate highways that end in a “5,” it is a major cross-country, north-south route. I-35 runs from Laredo, Texas, near the Mexican border to Duluth, Minnesota, near the Canadian border.
I-35 was designated by the American Association of State Highway Officials (AASHO; now AASHTO) on August 14, 1957, as an original interstate highway from Laredo north to Duluth.
With a length of 1,568 miles, I-35 is the ninth-longest interstate highway, and the third-longest north-south interstate. Although it is generally considered to be a border-to-border highway, I-35 does not directly connect to either international border. I-35 also splits into I-35E and I-35W in the two states that are its two ends – in the Dallas-Fort Worth metroplex in Texas and in Minnesota’s twin cities of Minneapolis-St. Paul.
In addition to the Dallas-Fort Worth and Minneapolis-St. Paul metropolitan areas, the major cities that I-35 also connects to include (from south to north) San Antonio and Austin, Texas; Oklahoma City, Oklahoma; Wichita, Kansas; Kansas City, Missouri; and Des Moines, Iowa.
Note: Throughout this article, I-35 will be discussed from south to north.
History of I-35
Interstate 35 was one of the highways designated in the original Interstate Highway System (IHS) plan in the early 1950s.
As is the case with most of the original interstate highways, different sections of I-35 were built at different times in each state. Also, although construction may have been finished for the original interstate, most of the older interstate highways have been rebuilt (repaired, widened, rerouted slightly, overpasses and entrances/exits rebuilt, etc.).
Within Texas, Interstate 35 was an original interstate highway, and it was approved by the Texas State Highway Commission in 1962 with a length of 492 miles (which includes both Interstate 35E and 35W). Later in 1962 the segment of I-35 through Austin was among the first parts of the highway to be completed.
I-35 northbound begins at an intersection with Business I-35-A in Laredo, just north of the Rio Grande River and the international border between Mexico and the U.S. It has a 17-mile concurrency with US 83.
In San Antonio, I-35 is named the Pan Am Expressway. It has brief concurrencies with I-10/US 87 and I-410. I-37’s northern terminus is at a junction with I-35.
In Austin, I-35 is the Interregional Highway and has a concurrency with US 290 through the city’s downtown. Since I-35 first opened in the city, elevated express lanes have been constructed on either side of the original freeway. South of the town of Temple, I-35 is the current eastern terminus of I-14. In Waco, I-35 starts its concurrency with US 77. The campuses of both the University of Texas at Austin and Baylor University are located adjacent to I-35.
In Hillsboro, I-35 splits into I-35W and I-35E and for its run through the Dallas-Fort Worth area. The official mile markers, along with the route of US 77, follow I-35E through Dallas. I-35W, which is 85 miles in length, carries its own mileage from Hillsboro to Denton, as though it were an I-35 loop.
After passing through the Dallas-Fort Worth metroplex, I-35E and I-35W rejoin in Denton near the University of North Texas campus. The unified Interstate then continues north to Gainesville before crossing the Red River into Oklahoma.
I-35’s total mileage in Texas is now 504.15 miles. Within the state, the major cities served by I-35 include Laredo, Pearsall, San Antonio, Austin, Georgetown, Temple, Waco, Hillsboro, Waxahachie, Dallas, Denton and Gainesville.
Within Oklahoma, the first section of I-35 to open to traffic was the four-mile connection from U.S. 177 north to the Kansas Turnpike (on April 22, 1958). This connection is considered to be the first portion of an interstate highway to cross state lines and connect to another state. By 1962, Interstate 35 was open to traffic from Purcell north to the Kansas Turnpike. This included an overlap with Interstate 40.
Certain portions of what became I-35 in Oklahoma City were built in 1953, before the IHS was created. Through Norman, I-35 opened in June 1959. In Moore, it opened in two parts: the northern half, which connects Moore to Oklahoma City, opened in January 1960. The southern half, which links Moore to Norman, opened to traffic in June 1967.
The original construction of I-35 was completed in Oklahoma in 1971, when parts of the highway running through Carter and Murray counties opened to traffic. The highway’s total length in Oklahoma is just under 236 miles.
I-35 through Oklahoma largely parallels US 77. This is due to a large degree to efforts of the towns of Wynnewood, Paoli and Wayne, which fought to keep I-35 as close as possible to US 77. The towns’ effort was successful because then-Governor Henry Bellmon threatened to build a toll road rather than I-35, and legislation was passed that would have prevented state funds to be used for the construction of I-35 if it were more than one mile from the U.S. Route.
The interstate runs from the Red River at the Texas border to the Kansas state line near Braman. It passes through or adjacent to many of the state’s major cities. From south to north, these cities include Ardmore, Pauls Valley, Purcell, Norman, Moore, Oklahoma City and Edmond. I-35 has a major junction with I-40 in downtown Oklahoma City. There are also spurs into I-235 through the north central section of the city.
Between the Oklahoma state line and Emporia, I-35 is part of the Kansas Turnpike. That section of I-35 that overlays the Kansas Turnpike was built in 1955 and 1956, and the entire turnpike opened to traffic on October 21, 1956.
US 24, US 40, US 69, US 75 and US 81 were considered as potential interstate routes by Kansas on June 5, 1945. The Kansas State Highway Commission submitted plans on May 22, 1946, that resulted in three primary routes to be considered by the federal government. Route 1 became I-70, Route 2 became I-35 and Route 3 became Kansas State Road 66.
Those sections of the Kansas Turnpike that carry I-35, I-70 and I-470 were approved as part of the IHS by the Federal Highway Administration in 1957. The remaining unnumbered section of the Kansas Turnpike was designated I-335 in 1987.
I-35 replaced U.S. 50 between Emporia and Olathe. At Emporia, I-35 leaves the Kansas Turnpike and has its own alignment. This free section of I-35 provides access to Ottawa before entering the Kansas City metropolitan area.
During the late 1960s, construction of most of the original I-35 in the state (from Ottawa to Kansas City, excluding the segment around Emporia) was finished and opened to traffic. The 10-mile section of the highway east from the Kansas Turnpike around Emporia opened to traffic in 1974, which was the end of construction of the original I-35 in Kansas. The total length of the highway in Kansas is 235.51 miles.
I-35 enters Missouri just two miles southwest of Kansas City’s Central Business District. It merges with Southwest Trafficway and Broadway, where it widens and continues north to downtown Kansas City. There, I-35 is the west and north legs of the downtown freeway loop. On the north edge of the loop, I-35 and I-70 merge. After the loop, I-29 begins and runs concurrently with I-35.
The two interstate highways cross the Missouri River together on the Christopher S. Bond Bridge and then split. I-35 heads north to Cameron, Missouri, and then continues northward to the Iowa state line.
Within the six states that I-35 runs through, its shortest distance is in Missouri (114.74 miles).
When it was originally planned, I-35 was to follow the alignment of US 69 from Des Moines to the Minnesota border. Interstate 35 does run parallel to US 69 for much of its course through the southern part of Iowa. However, the segment of I-35 between Mason City and US 20 near Iowa Falls was delayed by the business and political leadership of Mason City, which lobbied for the route of I-35 to be moved closer to the city.
On September 1, 1965, the alignment was changed to parallel US 65 through northern Iowa, which brought I-35 much closer to Mason City. However, in doing so, the route created a long diagonal section; local farmers objected to their farms being bisected. The resulting lawsuits delayed I-35 for a number of years.
Because of the lawsuits, I-35 opened in Iowa in phases between 1958 and 1975; its total length in the state is 218.33 miles. The farmers’ lawsuits were rejected in a November 1972 ruling; the final segment of I-35 (as originally planned in the 1950s) to open was in north-central Iowa (the segment between Mason City and US 20 near Iowa Falls, which opened in 1975).
Minnesota is the northernmost state that I-35 runs through. The first section of I-35 to open in the state was between Owatonna and Medford in 1958. The last section of Interstate 35E through St. Paul opened to traffic on October 15, 1990.
In Duluth, I-35 ends after a series of “cut and cover tunnels” that were the largest public works projects in northeastern Minnesota. This section of the highway was proposed by the Federal Highway Administration in 1958.
Within Minnesota, I-35 runs for 259.69 miles and connects the cities of Albert Lea, Owatonna, Faribault, St. Paul and Duluth.
An overlap of I-35 and I-90 was originally proposed, but this was changed in 1964. The following year, I-35’s route was changed again, running south midway between US 65 and US 69, which coincided with the changes in Iowa described above.
As in the Dallas-Fort Worth metroplex, I-35 splits again into I-35W and I-35E in the Minneapolis–St. Paul area. In both directions between MN 5 and I-94, trucks weighing more than 9,000 pounds are banned from I-35, and the speed limit drops to 45 mph. This section was not finished until the late 1980s (although the route had been cleared and graded earlier) due to opposition from a nearby historic neighborhood. The four-lane, “parkway” design was a political compromise. The truck bypass for this section is signed as I-494 and I-694 to the east of St. Paul.
I-35’s entire length in Minnesota (from the Iowa state line to its end in Duluth), is designated the Red Bull Highway, after the 34th Infantry (Red Bull) Division.
A recent FreightWaves Classics two-part article covered the collapse of the I-35W bridge on August 31, 2007, and other bridges in the United States. Read Part 1 and Part 2 of “Fix the bridges” by following the links.