sentences:  To the south, which is also co-signed with I-69, it is the Southwest Freeway (from Rosenberg to Downtown Houston).The stretch of the Southwest Freeway just west of The Loop was formerly one of the busiest freeways in North America, with a peak AADT of 371,000 in 1998.US 59 (overlapped by US 71) actually straddles the border between Texas and Arkansas north of I-30 near Texarkana, with the east side of the highway on the Arkansas side and the west side of the highway on the Texas side.