In 1917 the route followed present day Interstate 10 eastward from El Paso to roughly Esperanza. From there the road was proposed to go to Presidio (not built) and followed FM 170 from there to near Lajitas. It was proposed from there to hug the Rio Grande through Big Bend and towards Langtry (again, never built) where it would have met up with present day U.S. Highway 90. On US 90, the road would have gone into Del Rio and, via present day US 277, into Eagle Pass and though to Paso de Francia via present day FM 1021 and FM 1472 to Laredo. The Paso de Francia to Laredo segment was again, at the time never built. From Laredo to Pharr the road would have followed present day U.S. Highway 83. At Pharr, a spur of SH 12 would have continued east on US 83 to Brownsville. The main road went north on from Pharr on U.S. Highway 281 to Falfurrias then East on SH 285 into Riviera and north on U.S. Highway 77 towards Victoria, through to Houston on U.S. Highway 59 and finally US 90 to Orange. The route from Kingsville to Brownsville was determined on July 3, 1917.