State Highway 78
SH 78, mainline in red, business routes in blue
Route information
Maintained by TxDOT
Length	90.83 mi[1] (146.18 km)
Existed	1923–present
Major junctions
South end	I-30 in Dallas
Major intersections	I-635 in Garland US 380 in Farmersville US 69 in Leonard US 82 in Bonham
North end	SH-78 at Texas–Oklahoma state line
Location
Country	United States
State	Texas
Highway system
Highways in Texas Interstate US State Toll Loops Spurs FM/RM Park Rec
← SH 77 → US 79

State Highway 78 (SH 78) is a state highway that follows surface roads in a predominantly southwest-to-northeast direction in the Dallas area before traveling 90 miles (145 km) north-northeast to the Oklahoma State border.

Route description

The highway's southern terminus is at Interstate 30 in Dallas. From there, it follows Grand Avenue along White Rock Lake and then Garland Road into Garland as it passes Interstate 635. In downtown Garland, Highway 78 follows the central streets of Avenues B and D before joining Lavon Drive and moving northeastward.

It continues to the northeast through Sachse and Wylie, crossing between Lake Ray Hubbard and Lake Lavon. It passes through Lavon before turning north through Farmersville and Blue Ridge. At SH 160, just before SH 121, SH 78 turns east, continuing to Leonard before turning northeast again to Bailey. At Bailey, SH 78 turns north and cuts through Bonham (as Center Street) to reach Sowell's Bluff Bridge (a 1938 truss bridge) over the Red River.^[2]

The route continues as Oklahoma State Highway 78 through Durant to its terminus at Tishomingo.

History

The highway was originally designated on August 21, 1923, from Dallas to Bonham, replacing SH 5C.^[3] On May 19, 1924, the section from Desert to Bonham was cancelled. SH 78 was instead rerouted on its current route north of Desert to Bonham.^[4] On March 30, 1933, SH 78 was extended to Oklahoma.^[5] On October 6, 1943, SH 78 was extended south to Loop 12. On June 21, 1951, the section from US 67 to Loop 12 was renumbered to Spur 244. US 67 was rerouted over current I-30, and the old route was transferred to rerouted SH 78 and the rest northeast of SH 78 was renumbered to FM 7, which was cancelled and transferred to SH 66 on November 30, 1961.

SH 78A was a spur designated on May 9, 1927 from Desert to Bells. This spur was renumbered as SH 160 on March 19, 1930.

Flooding

In 1990, SH 78 was flooded, as engineers at the Lake Lavon Dam decided to release the water from the lake into the East Fork of the Trinity River. For a month and a half, the traffic going between Wylie and the eastern portion of Collin County was diverted to go through the city of Rockwall, a nearly 20-mile (32 km) detour. The railroad that ran adjacent to the highway was completely washed out, and significant shoulder damage was done to the highway.

Junctions

County	Location	mi	km	Destinations	Notes
Dallas	Dallas	0.0	0.0	I-30 (R.L. Thornton Freeway)	Southern terminus; I-30 exits 48B-49A
		4.2	6.8	Loop 12 (Buckner Boulevard)
		7.0	11.3	Spur 244 west (Northwest Highway) to I-635
	Garland	7.3	11.7	I-635 west (Lyndon B. Johnson Freeway)	I-635 exit 12
		11.4	18.3	SH 66 east
		14.3	23.0	Pres. George Bush Turnpike	Interchange
Collin	Wylie	20.3	32.7	FM 544 west
		20.9	33.6	FM 2514 north (Ballard Avenue)
		21.4	34.4	FM 3412 west (Brown Street)
	Lavon	26.0	41.8	SH 205 south – Rockwall
		26.6	42.8	Bus. SH 78-G north – Lavon (Main Street/Geren Drive)
		27.5	44.3	Bus. SH 78-G south – Lavon (Main Street)
	​	28.6	46.0	FM 6 east – Caddo Mills
	​	30.2	48.6	Bus. SH 78-F north – Copeville
	​	32.4	52.1	Bus. SH 78-F south – Copeville
	Farmersville	37.4	60.2	US 380 – McKinney, Greenville	Interchange
		38.0	61.2	Bus. SH 78-E north (McKinney Street)
	​	39.4	63.4	Bus. SH 78-E south – Farmersville
	​	41.5	66.8	FM 2756 west
	​	46.8	75.3	Bus. SH 78-D north – Blue Ridge
	Blue Ridge	48.2	77.6	FM 981 – Blue Ridge, Celeste
	​	49.1	79.0	Bus. SH 78-D south – Blue Ridge
	​	53.1	85.5	SH 160 north to SH 121 – Whitewright
Fannin	​	56.2	90.4	FM 815 north – Trenton
	​	59.0	95.0	FM 981 north	South end of FM 981 overlap
	​	59.2	95.3	FM 981 south	North end of FM 981 overlap
	Leonard	62.2	100.1	FM 896 north
		62.7	100.9	US 69 south – Celeste	South end of US 69 overlap
		63.3	101.9	US 69 north / Spur 241 west – Whitewright	North end of US 69 overlap
	​	63.5	102.2	FM 1553 north
	Bailey	68.5	110.2	FM 816 south
		68.6	110.4	SH 11 – Whitewright, Wolfe City
	​	69.5	111.8	FM 1552 east
	​	70.4	113.3	FM 1553 west
	​	71.1	114.4	FM 68 east
	​	76.8	123.6	FM 1629 south
	​	77.6	124.9	FM 271 south – Bonham State Park
	Bonham	79.1	127.3	SH 56 – Ector, Dodd City
		79.4	127.8	Loop 205 (10th Street)
		81.0	130.4	US 82 – Sherman, Paris	US 82 exit 671
		81.9	131.8	FM 898 north
	​	82.8	133.3	SH 121 south – Melissa, McKinney
	​	85.9	138.2	FM 1753 west
	​	87.6	141.0	FM 1396 east
	​	90.0	144.8	FM 274 west
	​	91.4	147.1	SH-78 north (State Highway 78 Bridge at the Red River)	Continuation into Oklahoma
1.000 mi = 1.609 km; 1.000 km = 0.621 mi       Concurrency terminus        Tolled

Business routes

SH 78 has four business routes.

Blue Ridge business route

Business State Highway 78-D (Bus. SH 78-D) is a 2.618-mile (4.213 km) long business route that runs through Blue Ridge in northern Texas.^[6] The route use to be

Farmersville business route

Business State Highway 78-E (Bus. SH 78-E) is a 2.435-mile (3.919 km) long business route that runs through Farmersville in northern Texas.^[7]

Copeville business route

Business State Highway 78-F (Bus. SH 78-F) is a 2.409-mile (3.877 km) long business route that runs through Copeville in northern Texas.^[8]

Lavon business route

Business State Highway 78-G (Bus. SH 78-G) is a 1.101-mile (1.772 km) long business route that runs through Lavon in northern Texas.^[9]