These roads typically follow along local streets often along a former U.S. Route or state highway that had been replaced by an Interstate.

Along Interstate 35 (I-35), business routes are found in four states through which I-35 passes: Texas, Missouri, Iowa, and Minnesota.

The route's southern terminus is at northbound I-35 exit 38, just south of the Webb–La Salle county line.

It briefly travels westward, crossing under I-35 and then turns north along Main Street, paralleling the Union Pacific Railroad tracks to the west.

Within the Cotulla city limits, the route intersects SH 97 and Farm to Market Road 468 (FM 468).

The route's southern terminus is at I-35 exit 82; it travels northward, paralleling the Union Pacific Railroad tracks to the east.

Within the Dilley city limits, the route intersects SH 85 and FM 117 before ending at I-35 exit 86.

I-35-H begins at I-35 exit 185 and briefly runs along Schimdt Avenue before turning onto Elliot Knox Boulevard approximately 0.2 miles (0.32 km) north of I-35.

The highway turns toward the northeast and has an intersection with SH 46/Loop 337 before running through less developed areas of the town.

I-35-L) in Round Rock was commissioned on June 21, 1990, and followed the previous route of US 81 along Mays Street, from Hesters Crossing Road to Old Settlers Boulevard for approximately 4.5 miles (7.2 km).

I-35-V) in Alvarado runs along the former alignment of US 81 along Parkway Drive and is accessible from I-35W at exits 24 (both directions) and 26B (southbound only).

The route travels north along 5th Street and crosses FM 455 before ending at the northbound I-35 frontage road near milemarker 479.

Immediately after a grade crossing with a former Milwaukee Road railroad line, the route makes a right turn overlapping US 18.

The route follows US 18, which itself runs parallel to that old Milwaukee Road line until it curves away after North 14th Street.

I-35 BL ends at exit 194 on I-35, US 18 turns south in an overlap with I-35, and the road previously carrying both routes becomes US 18 Bus./Iowa 122.

The route begins at a quarter cloverleaf interchange with exit 8 and runs northwest along US 65, a four-lane at-grade divided highway.

I-35 Bus./US 65 makes a sharp right turn to the east onto Main Street (CHAS 46), while in the opposite direction is the southern beginning of Minnesota State Highway 13 (MN 13).

I-35 Bus./US 65/CHAS 46 runs straight east along a divided highway for a block and a half then begins to curve to the northeast until after it crosses a bridge over the Shell Rock River, then curves back to the east before the bridge over the first railroad line that two of these routes crossed downtown.

The route travels south to north through the business district of Faribault, a distance of approximately three miles (4.8 km).

The route travels south to north through the business district of Pine City, a distance of approximately three miles (4.8 km).