Texas State Highway 100

State Highway 100
Route information
Maintained by TxDOT
Length:	24.61 mi[1] (39.61 km)
Existed:	1926[2] – present
Major junctions
West end:	I-69E / US 77 / US 83 / FM 1421 at Russeltown
East end:	PR 100 at the Queen Isabella Memorial Causeway at Port Isabel
Highway system
Highways in Texas Interstate US State Toll Loops Spurs FM/RM Park Rec ← 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 Interstate 69E/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 Interstate 69E/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 its eastern terminus at the Queen Isabella Causeway, which continues across the Laguna Madre to South Padre Island as Texas Park Road 100.

Junction list

The entire route is in Cameron County.

Location	mi[3]	km	Destinations	Notes
​	0.0	0.0	I-69E / US 77 / US 83 / FM 1421 – Brownsville	I-69E exit 14; interchange.
​	3.5	5.6	FM 803
​	5.1	8.2	FM 1575
Los Fresnos	6.5	10.5	FM 1847 (Arroyo Boulevard)
Laguna Vista	19.1	30.7	FM 510 (Santa Isabel Boulevard)
Port Isabel	23.1	37.2	SH 48 west – Brownsville	Eastern terminus of SH 48
	24.6	39.6	PR 100 (Queen Isabella Causeway) – South Padre Island
1.000 mi = 1.609 km; 1.000 km = 0.621 mi

References

1. ↑ Texas Department of Transportation,
2. ↑ 1926 highway map
3. ↑ Google (August 29, 2014). "Texas State Highway 100" (Map). Google Maps. Google. Retrieved August 29, 2014.