South Main Street Overpass - Fort Worth TX The South Main Street Overpass is a bridge with an overall length of 1,335 feet including approaches that currently carries South Main Street over multiple BNSF Railway tracks near downtown Fort Worth, Texas. The Texas Highway Department oversaw the construction of the bridge under a special United States Bureau of Public Roads grade crossing program. The overpass originally separated the grade of South Main Street from the tracks of the Texas & New Orleans Railroad and the Gulf Colorado & Sante Fe Railway. Contractor Purvis & Bertram built the bridge from 1936 to 1937 for $257,000 using federal aid funds.