Interstate 19

Interstate 19 Arizona
Nogales, AZ ↔ Tucson, AZ•63.35 miles•0 Branch Routes

Overview

Interstate 19 connects Nogales and Mexico with I-10 and Tuscon in southern Arizona. The freeway curves west around Crawford Hill from Grand Avenue (old U.S. 89) and the international border to bypass Downtown Nogales north to Arizona State Route 189. North from Rio Rico, I-19 parallels the Santa Cruz River to Tubac, Green Valley and the south suburbs of Tucson. The lone six lane section joins SR 86 with I-10 at South Tucson.

Costing $54 million, the Ajo Way Traffic Interchange project got underway in March 2016. Completed in March 2018, Phase I rebuilt the six-ramp parclo exchange with SR 86 and Ajo Way into a single point urban interchange (SPUI). Additional work added sound walls along I-19 from Ajo Way south to the Michigan Avenue pedestrian bridge.4 Started in July 2018, Phase II of the project expanded southbound I-19 and constructed a braided ramp system between the off-ramp at Exit 98 to Irvington Road and the entrance ramp from Ajo Way . Work on I-19 northbound added an auxiliary lane from Irvington Road to SR 86 / Exit 99, sound walls, and a new pedestrian bridge at Michigan Avenue by mid-January 2020. Costing $32 million, construction on Project II ran through Spring 2020.13,14

Mileage by State

Arizona63.35 mi

Data Sources

December 31, 2021 Interstate Route Log and Finders List

High Priority Corridor

Interstate 19 from Nogales to Tucson is part of High Priority Corridor 26: CANAMEX Corridor.

Parallel U.S. Routes

Interstate 19 ultimately replaced the original route of U.S. 89. Some old segments of U.S. 89 at Tucson and Nogales were incorporated into Business Loops for I-19. The Tuscon business route was eventually decommissioned.

History

Interstate 19 opened initially from Rico Rico Drive (Exit 17) to Palo Parado Road (Exit 25) in 1966. A 6.8 mile long section between Chavez Siding Road and Canoa Ranch was finished in 1977.15 That left two segments to build and the freeway was completed in 1979 when the section from Tubac (Exit 34) to Chavez Road (Exit 40) opened to traffic. See the I-19 Arizona guide for the rest of the time line.

One of the unique features of Interstate 19 is that the exit numbers and distance signs are based on the metric system, a first for the U.S. Interstate system. The use of metric units along I-19 was the result of a President Carter administration pilot project aimed to have the United States adopt the system. The metric units also served as a hospitality measure for Mexican tourists headed north to Tuscon and Phoenix.

1969 map of Interstate 19 in Arizona
Initial portions of I-19 ran south from I-10 to Valencia Road (Exit 95) by 1965 and between Mariposa Avenue (Exit 4) and Palo Parado Road (Exit 25) by 1968.
1972 Map of Tucson, Arizona
The original trumpet interchange between Interstates 10 and 19 in Tucson - 1972 U.S. 89, truncated south of Flagstaff as approved by the American Association of State Highway and Transportation Officials (AASHTO) on June 15, 1992, was designated as Business Loop I-10 north of I-19 and as Business Loop I-19 south of I-10. The I-10 business loop was eventually decommissioned by the late 1990s.

Some of these metric signs were replaced between SR 86 / Ajo Way (Exit 99) and Interstate 10 (Exit 101) as part of the Interstate 10/19 Crossing interchange project. Signs installed during the project in 2004 used English units, while other replacements made since and further south retained the metric system. Vocal opposition from area business owners countered efforts from the Arizona Department of Transportation to switch all of I-19 over to English units.2

The Crossing

Commencing in June 2002, a $54.3 million project replaced the substandard trumpet interchange joining I-19 with Interstate 10 in Tucson. Designed with longer ramps as well as improved geometry, the three level interchange at The Crossing was built slightly west of the original exchange.5 Work added ten bridges and eight ramps and reconstructed I-10 between 22nd Avenue and 10th Avenue and I-19 south to Ajo Way / SR 86. 12th Avenue was also rebuilt between 29th and 38th Streets and ramps from I-10 to 22nd Street were combined with new ones at 29th Street.6 Ramps were also added between I-19 and Silverlake Road.

Concrete columns supporting flyovers at the exchange, including the 60 foot high span from I-10 west to I-19 south, are decorated with maize and sunflowers. Painted tan, green and gold, the artwork represents the maize once grown by the Tohono O'odham tribe near the interchange location. The design was approved following a series of public meetings where different options were presented.7 The Crossings project was formally complete with a dedication ceremony held on August 7, 2004.8

North End Interstate 10 ‐ Tucson, AZ

Interstate 19 North at Interstate 10

I-19 north at I-10 - Tuscon, AZ

Suburban frontage lines both sides of Interstate 19 from Irvington Road north to the SPUI (Exit 99) with Ajo Way and SR 86. The freeway proceeds north along side the Santa Cruz River to I-10 and Silverlake Road. 04/26/17

I-19 north at I-10 - Tuscon, AZ I-19 north at I-10 - Tuscon, AZ I-19 north at I-10 - Tuscon, AZ I-19 north at I-10 - Tuscon, AZ

Interstate 10 East at Interstate 19

I-10 east at I-19 - Tuscon, AZ

Interstate 10 continues east from Tucson to Benson, Las Cruces, New Mexico and El Paso, Texas while I-19 travels through the south Tucson suburbs and Green Valley over the ensuing 28 miles. 04/26/17

I-10 east at I-19 - Tuscon, AZ I-10 east at I-19 - Tuscon, AZ I-10 east at I-19 - Tuscon, AZ I-10 east at I-19 - Tuscon, AZ

Interstate 10 West at Interstate 19

I-10 west at I-19 - Tuscon, AZ

Interstate 10 proceeds west a half mile from 6th Avenue to the directional T interchange (Exit 260) with Interstate 19 south to Nogales and Sonora, Mexico. 04/26/17

I-10 west at I-19 - Tuscon, AZ I-10 west at I-19 - Tuscon, AZ I-10 west at I-19 - Tuscon, AZ

North End – Past Views  ‐ Tucson, AZ

Interstate 19 North at Interstate 10

I-19 north at I-10 - 2005

SR 86 travels westward from Exit 99 and Ajo Way to the Tohono O’odham Nation and SR 85, 12 miles from the community of Ajo. Photo by Eric Harkness (04/02/05).

I-19 north at I-10 - 2005 I-19 north at I-10 - 2005 I-19 north at I-10 - 2005

Interstate 10 at Interstate 19

I-10 west at I-19 - 2005

All guide signs along Interstate 10 west at I-19 were replaced to use Clearview font after 2008. Photo by Eric Harkness (04/02/05).

I-10 east at I-19 - 2001 I-10 west at I-19 - 2005 I-10 west at I-19 - 2005

South End Business Loop I-19 ‐ Nogales, AZ

Interstate 19 South at Business Loop I-19 / West Street

I-19 south at Western Av - Nogales, AZ

Western Avenue converges with Interstate 19 at Target Range Road and Exit 1B near Ephraim Canyon. The remaining 1.1 miles of I-19 curve east around Crawford Hill to Sonoita Avenue and Downtown Nogales. 04/26/17

I-19 south at SR 189 - Nogales, AZ I-19 south at Western Av - Nogales, AZ I-19 south at International St - Nogales, AZ I-19 south at International St - Nogales, AZ I-19 south at West St - Nogales, AZ Crawford St east at Business Loop I-19 - Nogales, AZ

Business Loop I-19 / Compound Street west at Interstate 19

Crawford St west at Sonoita Avenue, Nogales, AZ

Business Loop I-19 navigates along an S-curve south from Crawford Street outside Downtown Nogales to Interstate 19 via Sonoita Avenue and Compound Street. 04/26/17

Crawford St west at Sonoita Avenue, Nogales, AZ Sonoita Av south at Compound St / I-19 - Nogales, AZ I-19 north at West St - Nogales, AZ

References

  1. "Some I-19 metric signs going," Tucson Arizona Daily Star, January 19, 2004.
  2. "Arizona highway signs in metric units may change." The Arizona Republic, October 5, 2014.
  3. Building the I-10/I-19 Traffic Interchange, http://www.1019crossing.com Arizona Department of Transportation project web site.
  4. "ADOT wrapping up first phase of Ajo Way/I-19 improvements." Arizona Department of Transportation (ADOT) News. March 15, 2018. https://azdot.gov/adot-news/adot-wrapping-first-phase-ajo-wayi-19-improvements
  5. "Construction set for new I-10, I-19 interchange." Green Valley News & Sun (AZ), April 17, 2002
  6. "I-10/I-19 interchange construction to begin." Green Valley News & Sun (AZ), June 25, 2002.
  7. 1-10/1-19 interchange - Massive bridge is beginning to reveal its tri-level profile." Green Valley News & Sun (AZ), January 30, 2003.
  8. "I-10/I-19 work's end cause for celebration." Arizona Daily Star, The (Tucson, AZ), August 3, 2004.
  9. "Work begins on I-10 improvement project." Arizona Daily Star, The (Tucson, AZ), December 20, 2006.
  10. "Prince-to-29th I-10 project gets its symbolic start." Arizona Daily Star, The (Tucson, AZ), December 15, 2006.
  11. "I-10 work nearly done, months early." Arizona Daily Star, The (Tucson, AZ), August 3, 2009.
  12. "New I-10 lanes about to open: Milestone at The Crossing." Arizona Daily Star, The (Tucson, AZ), August 16, 2003.
  13. "Second phase of I-19/Ajo Way improvement begins in Tucson." Arizona Department of Transportation (ADOT) News. July 25, 2018. https://azdot.gov/adot-news/second-phase-i-19ajo-way-improvement-begins-tucson
  14. "New pedestrian bridge across I-19 offers easier access." Arizona Department of Transportation (ADOT) Blog, March 6, 2020. https://azdot.gov/adot-blog/new-pedestrian-bridge-across-i-19-offers-easier-access
  15. "Throwback Thursday: The when and where." Arizona Department of Transportation (ADOT) Blog, November 14, 2019. https://azdot.gov/adot-blog/throwback-thursday-when-and-where
Updated May 17, 2022