Texas State Highway 121
|Length:||85.563 mi (137.700 km)|
|Existed:||by 1939 – present|
|Southwest end:||I-35W / US 287 / US 377 / Spur 347 in Fort Worth|
|Northeast end:||SH 78 in Bonham|
State Highway 121, locally known as 121 as well as other local names such as Chisholm Trail Parkway, is a diagonal state highway, angling from southwest to northeast through north central Texas. It runs from downtown Fort Worth, Texas at the junction of Interstate 35W to Bonham, Texas, just north of a junction with U.S. Highway 82.
Between Fort Worth and Euless, SH 121 is known as the Airport Freeway (east of Euless, this name applies to SH 183). Between Grapevine and Coppell, it is known as the International Parkway. East of Coppell, the highway acts as the frontage road of the Sam Rayburn Tollway, a tolled freeway that runs northeast to McKinney. From McKinney to Melissa, the state highway is multiplexed with US 75 and the North Central Expressway. Northeast of here, SH 121 is a smaller road referred to in some places as the Sam Rayburn Highway.
Route description 
Sections between downtown Fort Worth and Grapevine, Texas are freeway, including a small segment near Hurst, Texas that coincides with Interstate 820. At Bedford, Texas it has an interchange with State Highway 183, the Irving freeway that leads toward Dallas; it has an interchange with State Highway 360, which leads toward Arlington, Texas, just to the west of the north entrance to the Dallas/Fort Worth International Airport, to which State Highway 121 gives access. At Grapevine it has interchanges with State Highway 114 and Interstate 635 before becoming a limited-access tollway that passes between Lewisville and Frisco.
It is very heavily traveled south and west of McKinney and has become an urban highway due to the rapid growth of the Dallas-Fort Worth Metroplex. Service roads extending southwest to northeast along the corridor from Lewisville to McKinney are free of charge, however the main lanes within the right-of-way are tolled as part of the Sam Rayburn Tollway operated by the North Texas Tollway Authority (NTTA). The highway's northeastern half is primarily two lanes wide and carries significantly less traffic.
It meets Interstate 35E at Lewisville, Texas, State Highway 289 near Frisco, Texas, U.S. Highway 75 and U.S. Highway 380 in McKinney, Texas, U.S. Highway 69 at Trenton, Texas, and State Highway 78 just north of Bonham.
Construction began in 2009 on the extension of 121 south from Fort Worth to Cleburne, Texas, as a toll road called Southwest Parkway in Tarrant County and Chisolm Trail in Johnson County. This section will be operated by the NTTA and the entire project, from IH 30 to U.S. 67 is expected to open to traffic in the fourth quarter of 2013.
In March, 2009, work was completed on a short stretch of TX 121 northeast of DFW Airport which upgraded 2 signalized at-grade intersections to a freeway, with overpasses at both intersections, clearing up a problem for rush-hour traffic.
Sam Rayburn Tollway 
In early 2007, the Spanish firm Cintra agreed to a $2.8 billion, 50-year deal where they would lease the highway from TxDOT, finish building and maintain it, and collect the tolls. However, critics of the deal questioned both its length—the contract allowed Cintra to collect tolls for 50 years—and the fact that the North Texas Tollway Authority (NTTA) was prevented from bidding on the contract. In addition, general opposition to the toll plan organized, pointing out that the segment through Denton County had already been paid for by taxpayer money.
To answer some of these complaints, Texas legislators pressed the Texas Department of Transportation to allow the NTTA to bid. The Authority announced their proposed bid in early May 2007, which would provide approximately $3.3 billion in road funding, but is based on traffic counts that differ from those used by Cintra.
On June 28, 2007, the Texas Transportation Commission announced it would pursue the proposal from the North Texas Tollway Authority (NTTA). 
Route history 
SH 121 was originally numbered in 1928 as a direct routing between Fort Worth and McKinney. By 1933, the route had been completed from Ft. Worth northeast through Grapevine to its intersection with U.S. Route 77 in far southern Denton County. In 1943, the ambitious plan to extend SH 121 northeast to Bonham was approved by TXDOT, a part of which absorbed Farm to Market Road 82 between Bonham and Randolph. But it wasn't until 1954 that the next section of this highway was completed between U.S. 77 at Lewisville and U.S. Route 75 near McKinney. The final section between McKinney and Trenton was not completed until 1964, including an extension around the western side of Bonham. In 1965, the section from downtown Fort Worth to Interstate 820 was transferred to newly completed freeway sections.
Exit/Junction list 
||This section contains a table that is missing mileposts for one or more junctions. Please help by|
|Tarrant||Fort Worth||Spur 347 west (Belknap Street) – Downtown Fort Worth||Continuation beyond I-35W|
|I-35W / US 287 / US 377 south – Denton, Waco|
|US 377 north (Belknap Street)||Northbound exit and southbound entrance|
|Maxine Street||Northbound exit and southbound entrance|
|Richland Hills||Handley-Ederville Road|
|I-820 south||South end of I-820 overlap.|
|SH 10 east / SH 183 west – Richland Hills||South end of SH 183 overlap; signed as exit 24A southbound|
|Pipeline Road, Glenview Drive||Signed as exit 23 eastbound|
|North Richland Hills|
|SH 26 / FM 1938 north – Tarrant County College Northeast Campus||Signed as exit 22A northbound|
|I-820 west||North end of I-820 overlap|
|Bedford-Euless Road||Signed as exit 22A northbound|
|FM 3029 north (Precinct Line Road) / Hurstview Drive|
|Norwood Drive, Brown Trail|
|Bedford||Bedford Road, Forest Ridge Drive, Brown Trail|
|Central Drive, Forest Ridge Drive|
|SH 183 east – D/FW Airport South Entry, Irving||No southbound exit; north end of SH 183 overlap|
|Murphy Drive, Euless Westpark Way||Northbound exit is via SH 183 east|
|FM 157 south / Cheek-Sparger Road|
|Stone Myers Parkway||Northbound exit and southbound entrance|
|SH 360 south – Arlington||Southbound exit and northbound entrance|
|William D. Tate Avenue||Southbound exit is via SH 114 west|
|SH 114 west – Bridgeport||South end of SH 114 overlap; northbound exit is via Tate Avenue|
|Spur 103 (Main Street)|
|Bus. SH 114-L west (Texan Trail) to SH 26|
|SH 114 east – Irving, Dallas||North end of SH 114 overlap|
|Bass Pro Drive – Gaylord Texan|
|FM 2499 north (Grapevine Mills Parkway) – Flower Mound||No northbound entrance|
|Sandy Lake Road / Grapevine Mills Parkway / Freeport Parkway / SH 26 south||SH 26 accessible from southbound 121 only|
|Bus. SH 121-H north – Lewisville|
|Denton Tap Road|
|South end of Sam Rayburn Tollway|
|Lewisville||I-35E (US 77) – Denton, Dallas||Northbound exit to I-35E north is via MacArthur Boulevard exit|
|Marchant Boulevard, Huffines Boulevard|
|Bus. SH 121-H south / FM 2281 – Lewisville|
|FM 423 (Main Street) / Josey Lane – Little Elm, Carrollton|
|Plano Parkway/Paige Road|
|Plano||Spring Creek Parkway|
|Collin||Frisco (north side),
Plano (south side)
|Dallas North Tollway – Dallas, Prosper||Interchange|
|SH 289 (Preston Road)||Interchange|
|Hillcrest Road/Rasor Boulevard|
|FM 2478 (Custer Road)|
|Lake Forest Drive/Watters Road|
|North end of Sam Rayburn Tollway|
|US 75 south (Central Expressway) – Dallas||South end of US 75 overlap|
|Eldorado Parkway||Signed as exit 39|
|Spur 359 (Louisiana Street) / FM 3038 (Virginia Parkway)||Signed as exit 40A|
|White Avenue||Signed as exit 40B|
|US 380 (University Drive)||Signed as exit 41|
|Wilmeth Road||Signed as exit 42|
|Weston Road||Signed as exit 43|
|Telephone Road/Davis Road||Signed as exit 44|
|US 75 north (Central Expressway) – Sherman||North end of US 75 overlap|
|FM 545 (Sherman Street)|
|FM 455 (White Street) – Celina|
|FM 2662 (Houston Street)|
|Fannin||SH 160 – Whitewright, Farmersville|
|US 69 – Bells, Greenville||Interchange|
|Randolph||Bus. SH 121|
|SH 11 – Tom Bean, Commerce||Interchange|
|SH 56 – Bells, Honey Grove|
|US 82 – Sherman, Paris||Interchange|
|SH 78 – Durant, Farmersville||Northern Terminus|
- Transportation Planning and Programming Division. "Highway Designation File: State Highway No. 121". Texas Department of Transportation. Retrieved 2010-06-15.
- http://www.ntta.org/AboutUs/Roadways/SH121.htm "Sam Rayburn Tollway"
- http://www.ntta.org/NR/rdonlyres/3FFA8F0C-1525-445F-A169-8B47A341B396/0/NTTA_SWPCT_Brief.pdf", Southwest Parkway/Chisholm Trail Project Status Report March 2009 from the NTTA.
- http://www.wfaa.com/video/?z=y&nvid=344241 "Overpasses give non-stop route between Frisco and D/FW", WFAA-TV report, March 20, 2009.
|Wikimedia Commons has media related to: Texas State Highway 121|
- www.Texas121.org - Official Site[dead link]
- Denton & Collin County section of SH 121 - from dfwfreeways.info