Similar to I-35, I-69 splits into three letter-suffixed branches, I-69E, I-69C, and I-69W. U.S. Highways The United States Numbered Highways are a nationwide grid of highways, but unlike the Interstate Highway System, there is no minimum design standard for these highways. This is clearly evident as some stretches of the U.S. Highways in Texas are nothing more than a two-lane rural road, while others are urban freeways. Although the U.S. Highways have been replaced for the most part by Interstate Highways for through traffic, the U.S. Highways still serve as important regional connectors. Several notable examples of U.S. Highways that are built to freeway standards include US 75 and US 80 in Dallas, US 59 and US 290 in Houston, and US 90 and US 281 in San Antonio. The Interstate Highways have replaced several portions of the U.S. Highway network in Texas and as a result, they have been removed from the State Highway System. Several examples include US 81 from Fort Worth to Laredo in favor of I-35, US 75 from Dallas to Galveston in favor of I-45, and US 80 from Dallas to El Paso in favor of I-10 and I-20. State Highways SH 3, SH NASA Road 1, andSH OSR shields A State Highway (SH) is funded and maintained by the state. State Highways have been assigned numbers between 1 and 365 with a few exceptions. There is also a State Highway 495 (renumbered from Farm to Market Road 495), as well as canceled routes SH 550 (a temporary designation for what is now part of I-169) and SH 824 (a temporary designation for what was later part of SH 24). NASA Road 1 and State Highway OSR are also in the State Highway network. The first 26 state highways were designated in 1917. Highways are not organized by directionality of the highway, instead they are generally numbered as they were when first built in the 1920s and 1930s. Most suffixed routes were eliminated by 1939, though SH 75A existed from 1946 to 1994 to match Oklahoma's SH 75A. State Highway Loops and Spurs Loop, Spur and Beltway shields State highway loops and spurs are short links in the State Highway network. They are generally numbered chronologically, and the lower numbers are older routes. Thus, spurs and loops are not related to similarly numbered main state highways. Typically, a loop connects two state or national highways,