State Highway 155 or SH 155 runs from U.S. Highway 79 in Palestine northeastward via Frankston to State Highway 64 at Tyler; and from another point on SH 64 northward to junction of US 271 and State Highway 31; and then from a point on US 271 northeast of Tyler, northeastward via Big Sandy, Gilmer, Avinger to US 59 (Future I-369) at Linden, a total approximate distance of 111.75 miles (179.84 km).Nearly the entire route is a divided highway.