Texas State Highway 45
|Length:||11.482 mi (18.478 km)|
|Existed:||1985 – present|
|Beltway around Austin|
|West end:||RM 1826 in Austin|
|East end:||Loop 1 in Austin|
|West end:||RM 620 in Austin|
| US 183
|East end:||I-35 in Austin|
State Highway 45 is a highway loop around Austin, Texas that exists in two open segments. The official designation of SH 45 is such to form a complete loop around Austin, a distance of roughly 80 miles (130 km).
One segment is in southwest Austin and runs roughly southeast from Ranch to Market Road 1826 to the southern terminus of Loop 1 (Mopac Expressway). The roadway is a divided, four-lane facility with a wide median intended to accommodate a future freeway, after which the current lanes would serve as frontage roads.
The other segment is a toll road that forms a backwards C-shape along the boundary of Travis and Williamson County before bending down along the eastern edge of the Austin metropolitan area where it shares its route with SH-130.
Toll road expansion 
Before the 2002 Central Texas Turnpike Project (CTTP), SH 45 existed only as a short section of four-lane, divided highway in southwest Austin. The CTTP added a toll road that runs east from US 183 near Cedar Park, crosses I-35, bi-secting the La Frontera development, and meets SH 130 near Pflugerville. South of this interchange, SH 45 is co-signed with SH 130 to US 183 just south of Austin-Bergstrom International Airport. SH 45 then loops westward rejoining I-35 north of Buda.
SH 45 North is an approximately 13-mile (21 km) segment in the north Austin metropolitan area. The freeway's western terminus is at US 183 northwest of Austin in Cedar Park. For a distance, RM 620 travels concurrently with the frontage roads also designated as State Highway 45 (non-tolled). Heading east, the freeway intercepts Loop 1's northern terminus, bisects La Frontera and crosses I-35. This particular segment ends at SH 130 near Pflugerville, but the SH 45 designation continues southward along SH 130.
The Texas Department of Transportation had originally planned to complete construction of the entire 2002 CTTP in September 2007 but opened some sections of SH 45 North as early as October 31, 2006.
SH 45 Southeast is a 7.4-mile (11.9 km), tolled segment southeast of Austin, near Creedmoor, Texas. Roughly paralleling Farm to Market Road 1327, it is a four-lane, controlled-access facility that links SH 130 and US 183 to Interstate 35 north of Buda, Texas. It completes the SH 45 eastern bypass loop around the Austin metropolitan area.
Originally planned as part of the 2002 CTTP, SH 45 Southeast became the subject of controversy, delaying development and necessitating it as a separate project. In 2006, an environmental advocacy group filed a lawsuit in an effort to move the alignment further south. By the summer of the same year, the Federal Highway Administration approved a new environmental impact study affirming the existing alignment, and a federal judge dismissed the case, clearing the way for construction, which began in Summer 2007. SH 45 Southeast was opened to traffic on May 7, 2009.
SH 45 Southwest is a proposed link between the existing non-tolled SH 45 terminus at Loop 1 and Ranch to Market Road 1626 to the east. It could be tolled, especially if it included a freeway component. But if built, SH 45 Southwest would still require a segment between RM 1626 and I-35 to connect to the other tolled segments of the highway.
This missing link was one source of controversy surrounding the alignment of SH 45 Southeast. Opponents claimed the proximity of the southwestern and southeastern sections would create more pressure to connect the two and that, if built, the link would encourage development on or near environmentally sensitive land.
History of the SH 45 designation 
State Highway 45 was originally designated in 1919 as a route from Bryan to Jasper. By 1933, large portions of the highway were still under construction along the proposed route. By 1938, the road was complete from Roan's Prairie to the Louisiana border, with small portions remaining as a dirt road. Within the same year, the highway from Huntsville to Jasper had been transferred to U.S. Highway 190, the stretch from Jasper to the Louisiana border transferred to SH 63, and the section from Roan's Prairie to Huntsville redirected north to Crockett. In 1960, the stretch from Huntsville to Crockett was transferred to SH 19. The next year, the rest of SH 45 was canceled and transferred to SH 30.
Exit list 
|Williamson||Austin||RM 620||Westbound exit, eastbound entrance|
|US 183 / 183A Toll Road north||Westbound exit, eastbound entrance|
|Lake Creek Pkwy|
|FM 734 (Parmer Ln)|
|McNeil Rd||No Westbound exit|
|Loop 1 south||West end of Loop 1 overlap|
|Round Rock||La Frontera Blvd, CR 172|
|I-35 north – Waco||East end of Loop 1 overlap|
|A.W. Grimes Blvd|
|Donnell Dr||No westbound exit|
|Travis||Pflugerville||Heatherwilde Blvd||No westbound exit|
|SH 130 / FM 685 (Kelly Ln)|
|SH 130 – Waco, Austin||North end of SH 130 concurrency|
|429||Pflugerville Pkwy||Northbound exit and southbound entrance|
|432||Cameron Rd||Southbound exit and northbound entrance|
|435||Gregg Manor Rd||Northbound exit and southbound entrance|
|Austin||436||FM 734 (Parmer Ln)|
|437||US 290 – Houston, Austin|
|439||Blue Bluff Rd||No northbound exit|
|446||Harold Green Rd|
|Austin||449||SH 71 – Houston, Austin|
|Mustang Ridge||457||Maha Loop|
|458||US 183 / SH 130||South end of SH 130 concurrency|
|Creedmoor||FM 1625 (Turnersville Road)|
|North Turnersville Road|
|I-35 – Austin, San Antonio|
|Current gap in highway|
|Austin||Loop 1 north (Mo Pac Expressway)|
- Wear, Ben. Fifth toll road clears legal hurdles. Austin American-Statesman, accessed December 14, 2006.
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