I-45 replaced U.S. Highway 75 (US 75) over its entire length, although portions of US 75 remained parallel to I-45 until its elimination south of Downtown Dallas in 1987. At the south end of I-45, State Highway 87 (SH 87, formerly part of US 75) continues into downtown Galveston. The north end is at I-30 in Downtown Dallas, where US 75 used the Good-Latimer Expressway. A short continuation, known by traffic reporters as the I-45 overhead, signed as part of US 75 and also part of unsigned I-345, continues north to the merge with the current end of US 75. Traffic can use Spur 366 (better known locally as the Woodall Rodgers Freeway) to connect to I-35E at the north end of I-345.
I-45 replaced US Highway 75 (US 75) over its entire length although portions of US 75 remained parallel to I-45 until its elimination south of Downtown Dallas in 1987 At the south end of I-45 State Highway 87 (SH 87 formerly part of US 75) continues into downtown Galveston The north end is at I-30 in Downtown Dallas where US 75 used the Good-Latimer Expressway A short continuation known by traffic reporters as the I-45 overhead signed as part of US 75 and also part of unsigned I-345 continues north to the merge with the current end of US 75 Traffic can use Spur 366 (better known locally as the Woodall Rodgers Freeway) to connect to I-35E at the north end of I-345