Texas State Highway 100

State Highway 100
Route information
Maintained by TxDOT
Length:	24.61 mi (39.61 km)
Existed:	1926 – present
Major junctions
West end:	US 77/US 83/FM 1421 at Russeltown
East end:	Park Road 100 at the Queen Isabella Memorial Bridge at Port Isabel
Highway system
Highways in Texas Interstate • US • TX (Loops – Spurs – Rec – FM) ← SH 99 SH 101 →

State Highway 100 or SH 100 is a Texas state highway that runs 24 miles (39 km) between "Russeltown" and Port Isabel. It was designated in 1926 along its current route. Its western terminus is at U.S. Highway 77/83 and ends at the western end of the Queen Isabella Memorial Causeway at Port Isabel. The route continues as Texas Park Road 100 east and north to a dead end on South Padre Island.

History

SH 100 was designated in 1926 on its current routing in Deep South Texas. Since its initial construction, the only change in the routing is in the city of Port Isabel, where the route was transferred to separate one way surface streets to better handle flow onto the Queen Isabella Causeway.

Route description

SH 100 begins at an intersection with U.S. Route 77/U.S. Route 83 and Farm to Market Road 1421 at unincorporated Russelltown (formerly known as Barreda). The route travels due east, passing through downtown Los Fresnos. The route continues east before turning northeast where it formerly met Old Port Isabel Road, which connected Brownsville and Port Isabel. At this point the route becomes a 4-lane divided highway. The route continues northeast and east around the northern edge of Bahia Grande before reaching the southmost edge of Laguna Vista. The route then turns southeast, running along the coast of the Laguna Madre. Continuing southeast, it passes through the town of Laguna Heights, before reaching the city of Port Isabel. It reaches the eastern terminus at the Queen Isabella Causeway, which continues across the laguna Madre to South Padre Island

Junction list

County	Location	Junction	Notes
Cameron		US 77 / US 83 / FM 1421
		FM 803
		FM 1575
	Los Fresnos	FM 1847 (Arroyo Blvd)
	Laguna Vista	FM 510 (Santa Isabel Blvd)
	Port Isabel	SH 48	eastern terminus of TX 48
		PR 100