Simplify the following text for a Grade 6 native English-speaking person.
Original: The highway was first designated in 1959 as a route between Corpus Christi and San Antonio . Construction in the urban areas of Corpus Christi and San Antonio began in the 1960s and the segments of the Interstate Highway in rural areas were completed by the 1980s .
Simplified: It goes from Corpus Christi north to San Antonio .