Interstate 35 splits into Interstates 35E and 35W to serve Dallas (east) and Fort Worth (west). This is one of two split route designations (as evidenced by letter suffixes), the other being in Minnesota along Interstate 35. An interesting feature of Interstate 35W is the presence of Business Loop I-35W in Alvarado, near the junction with U.S. 67. This is the only remaining suffixed Interstate business route.
History of Split Routes
In their guidelines of signing Interstates, the American Association of State Highway and Transportation Officials (AASHTO) mandated that all suffixed Interstate highways be removed from the Interstate system in the late 1960s and 1970s. This resulted in many changes to the system, including:
Interstate 5W to Interstate 505 and Interstate 580 (Oakland to south of Tracy) in California
Interstate 15E to Interstate 215 in California (former U.S. 395)
Interstate 15W to the Western Interstate 86 in Idaho
Interstate 35 to Interstate 135 in Kansas
Interstate 70N to Interstate 70 and Interstate 70S to Interstate 270 in Maryland
Interstate 75E to Interstate 75 in the Tampa Bay Area (original Interstate 75 was renumbered Interstate 275)
Interstate 80N to Interstate 680 in Iowa
Interstate 80N to the Western Interstate 84 in Oregon, Idaho, and Utah
Interstate 80S to Interstate 76 in Colorado
Interstate 80S to Interstate 76 in Ohio, Pennsylvania, and New Jersey
Interstate 81E to Interstate 380 in Pennsylvania
Most of these conversions were completed during the 1960s and 1970s. The Western Interstate 84 was among the last, as it was converted by 1980. However, there are two exceptions remaining in the system: Interstate 35 splits twice into Interstate 35E and Interstate 35W, once in the Dallas/Fort Worth metro area and again in the Minneapolis/St. Paul metro area. The reason these split routes still remain is that neither city wanted to relinquish the routing of Interstate 35. AASHTO gave in to these demands, and the split suffixed routing remains in both Texas and Minnesota.
Interstate 35W was built in stages between the early 1950s and the late 1960s.1
Situated well to the south of the Dallas/Fort Worth Metroplex, Interstate 35 splits into its East/West counterparts. This photo looks at Exit 370, where U.S. 77 splits away from Interstate 35 after a 36 mile marriage that began in Waco. The mainline transitions to Interstate 35E and thus retains the Interstate 35 exit numbering scheme. Interstate 35W departs from the left within one-half mile. Photo taken by Marc Welby (08/00).
Perspective from Interstate 35E south
Two miles south of the Interstate 35E/W merge, is this sign on Interstate 35E southbound retaining button copy. A return ramp to Interstate 35W/Fort Worth is afforded to southbound motorists. The landscape however, is relatively rural, stark in contrast to the northern terminus of the split Interstates at the growing suburb of Denton. Photo taken by Justin Cozart (08/02).
The exit for Interstate 35W at the south end is unnumbered (unlike at the northern terminus - Exit 467). Traffic continuing south transitions back into Interstate 35, picking up U.S. 77 after the Exit 370 interchange just outside of Hillsboro. 32 miles separate this merge from the city of Waco. Photo taken by Justin Cozart (08/02).
This is the first signage for the pending split between Interstate 35E and Interstate 35W. Interstate 35 retains four lanes at this point, with the Texas standard frontage road system on both sides of the freeway. The Denton city limits encompass over ten miles of the route. Photo taken by Jeff Morrison (12/28/05).
Formerly, this two-mile advance sign was the first signage prior to the Interstate 35 split. It was a button copy sign. Vidcap taken 01/96.
Prior to the Farm to Market Road 1515 interchange, this mileage sign provides the distance to the Interstate 35 split near Denton. Photo taken by Jeff Morrison (12/28/05).
The last southbound exit of Interstate 35 is at Exit 468/Texas Farm to Market Road 1515 serving Denton Municipal Airport. Unlike at the southern split of Interstate 35E/W, Interstate 35W departs from the right and receives an Exit number. Photo taken 01/96.
A second view of Exit 468, one-half mile north of the split. It appears that the signs Pictured in the above photograph are still in place on Interstate 35 southbound. Most other mainline signage in the Dallas area saw replacement between 1996 and 2000. Photo taken by Eric Stuve (12/16/02).
Interstate 35 disappears into the troposphere while Interstate 35E and 35W take shape at Exit 467. The flyover in the background allows northbound Interstate 35E traffic to return southward via Interstate 35W. Interstate 35E travelers will reach the city limits of Dallas in 27 miles and Interstate 35W travelers will see Fort Worth in 25 miles. Vidcap taken 01/96.
Replacements of the button copy signs Pictured above. Note that the Exit 467 guide sign is no longer in place, yet the lighting fixtures for all however still are. The right-hand panel is missing its Interstate 35W shield. Photo taken by Jeff Morrison (12/28/05).