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Sun Tran

Public transit system serving Tucson, Arizona

Image credit is listed at the end of this article.

Sun Tran is the public transit system serving the city of Tucson, Arizona. In 2025, the system had 18,315,300 rides, or about 56,500 per weekday as of the second quarter of 2026. 100% of the fleet utilizes clean-burning fuels, such as compressed natural gas (CNG), biodiesel, and hybrid technologies. In addition to more than 40 bus routes, the system also includes the Sun Link modern streetcar line.

01History

Predecessors

According to David Leighton, historian for the Arizona Daily Star newspaper, Sun Tran's history began in 1897 with the organization of the Tucson Street Railway, which by the following year was providing Tucsonans with regular mule-powered streetcar service. Streetcar tracks existed in parts of present-day downtown and to the University of Arizona. Within a few years, lack of profit caused the company to be sold and it was reorganized as Tucson Rapid Transit Co. (TRT). It shortly came under common ownership with Tucson Gas, Electric Light and Power Co.

By 1906, mules were replaced by electricity as the driving force behind the streetcars in Tucson. Four years later, TRT published its intent to increase the amount of track for its electric cars but insufficient money prevented this from occurring. In 1910, TRT owner United States Light and Traction was acquired by the newly formed Federal Light and Traction.

In October 1925, Tucson Rapid Transit Co., having realized that buses were more flexible and economical to run than streetcars and were the future of public transportation in the Old Pueblo, bought the White Star Bus Line. This small bus company would become the basis for TRT's bus service in town. Also around the same time, Roy Laos Sr., noting the lack of transit service to the south and west sides of town founded the Occidental Bus Line to serve these areas. Laos' bus service would later be called Old Pueblo Transit.

In 1930, control of Federal Light and Traction was acquired by Cities Service. On January 1, 1931, Tucson Rapid Transit formally ended all electric streetcar service in town. From this day forward it became strictly a bus company. Five years later, Jacob M. Bingham established the Mountain View Bus Line with one bus. His goal was to provide service to outlying areas that TRT didn't serve but turning a profit or even just paying his bills was difficult and soon enough TRT bought his small enterprise.

During World War II, ridership increased to a large degree, in part due to tire and fuel rationing that was carried out to support the war effort. The secondary reason for the surge was the need for public transportation for workers in the growing defense industry.

After the passage of the Public Utility Holding Company Act of 1935, Federal Light and Traction/Cities Service was forced to sell most of their operations. TRT was sold to W. Culver White, John B. Tigrett, A.V. Lindseth and L.A. Tanner. Tucson Gas & Electric was sold in a public offering.

In late 1951, the Hughes Missile Plant (now called Raytheon Missiles & Defense) was finished and was operating with a small number of employees. Competition for ridership to the new factory between Old Pueblo Transit and Tucson Rapid Transit became heated and OPT filed an injunction in court to prevent TRT from providing service for employees. Early the following year, the Arizona Corporation Commission decided against OPT and allowed TRT to also provide bus service to the plant.

Founding

The 1950s and 1960s saw a steady decline in riders for Tucson Rapid Transit. Even a change in ownership in 1965 to American Transit Corp. (and a name change to Tucson Transit Corp.) and the installation of air conditioners seemed to do little for the failing bus service. As a result, in 1969, the City of Tucson acquired TTC, changing the name to the City of Tucson Transit System.

In 1975, a contest was held to give a new name to the bus system, with Benjamin Rios, a 25-year-old University of Arizona architecture student from Mexico, submitting the winning entry: “Sun Tran.” His prize was a $150 portable television.

Three years later, Sun Tran bought its competition the Old Pueblo Transit Co. and the city had but one bus service for riders. The year 1987 saw the opening of the Roy Laos Transit Center at 205 W Irvington Road, and in 1991, the Ronstadt Transit Center opened in downtown, named for historic Tucson business leader Federico José María Ronstadt.

Unification

On January 22, 2009, a regional seamless transit system was unveiled that helps to better unify the various public transit services in and around the Tucson metropolitan area. One change was the renaming of several of the services under the "Sun" moniker: the Sun Tran express bus routes become Sun Express; Van Tran (paratransit) becomes Sun Van, circulator routes in outlying areas become Sun Connect, and RideShare (carpooling) becomes Sun RideShare. Along with this name change comes a new logo and color scheme, replacing the old red, yellow, and white with a blue, yellow, silver, and white livery. The new livery was introduced into service on February 16, 2009, with the addition of 47 new Sun Tran buses and 42 Sun Van (formerly Van Tran) paratransit vehicles to the fleet.

Sun Connect service started on May 4, 2009, under the name Sun Shuttle, with routes that serve the communities of Casas Adobes, Tucson Estates, Ajo, Oro Valley, Rita Ranch, Marana, Avra Valley, Tohono O'odham Nation, Green Valley, and Sahuarita.These transit services are operated by the Regional Transportation Authority of Pima County (RTA).

In 2010, Sun Tran received shipment of its first bus using hybrid technology and two years later Sun Tran's Northwest Bus Facility located at 3920 N. Sun Tran Blvd was completed.

In summer of 2023, Sun Tran released their Comprehensive Operational Analysis, a pseudo bus network redesign that would increase frequency, realigning and extending routes and improving access and quality of service.

Ronstadt Transit Center in 2019
Ronstadt Transit Center in 2019

02Services

Sun Tran

Sun Tran operates 29 regular fixed bus routes. Most routes provide service from 6 am to 11 pm. A few routes provide service until midnight. Sun Tran does not provide overnight service.

Current routes

Route No. Route Name Termini Major Streets/Areas Serviced Notes
1 Glenn/Swan Ronstadt Transit Center, Downtown Swan Road/29th Street Downtown, Main Gate Square, University of Arizona, Park Avenue, Glenn Street, Swan Road.
  • Route was restructured in 2015 and service on 29th St was eliminated.
2 Tucson Marketplace Banner University Medical Center-Southern Campus Ronstadt Transit Center, Downtown Irvington Road, Country Club Road, Campbell Avenue, 36th Street, Pueblo Gardens, Downtown.
3 6th St./Wilmot Pima Community College (PCC) East Pima Community College (PCC) West Stella Road, Wilmot Road, 5th Street, 6th Street, University of Arizona, Downtown, St Mary's Road, Anklam Road.
4 Speedway Broadway/Houghton Park & Ride (1st segment)
Udall Transit Station (2nd segment)
Ronstadt Transit Center, Downtown Speedway Boulevard, Harrison Road, Kolb Road, University of Arizona, Downtown.
  • Route 4 rerouted from Golf Links/Kolb Park & Ride to Udall Transit Station in 2026
5 Pima/W. Speedway Udall Transit Station Pima Community College (PCC) West West Speedway Boulevard, University of Arizona, Pima Street, Tanque Verde Road, Udall Park.
6 Euclid Ave./N. 1st Ave. Ronstadt Transit Center, Downtown Tohono Tadai Transit Center Downtown, Main Gate Square, University of Arizona, Euclid Avenue, 1st Avenue.
  • Original Route 6 was restructured and split into Route 6 and Route 25 in 2015.
7 22nd St. Broadway/Houghton Park & Ride Ronstadt Transit Center, Downtown Downtown, 22nd Street
    8 Broadway Ronstadt Transit Center, Downtown Broadway/Houghton Park & Ride Downtown, Broadway Boulevard
    • Original Route 8 was restructured in 2015 and was split into Route 8 and Route 18.
    • Route 8 was restructed again in 2026 to merge with 108X and eliminate Udall Transit Station branch, with all trips traveling to Broadway/Houghton Park & Ride.
    9 Grant Pima Community College (PCC) West Pima Community College (PCC) West Grant Road, Kolb Road
    • Route 9 was merged with the former Route 20 in 2016, to create a continuous route on Grant Road.
    • Route 9 no longer services the University of Arizona and Downtown.
    • Route 9 was rerouted from Udall Transit Station to Pima Community College in 2026.
    10 Ruthrauff Davis Avenue/Ruthrauff Rd Ronstadt Transit Center, Downtown Ruthrauff Rd, Romero Rd, River Road, Miracle Mile, Oracle Road, Downtown.
    11 Alvernon/Ajo Ajo Way/Mission Road (1st segment)
    Tucson International Airport (2nd segment)
    Dodge Boulevard/River Road Alvernon Way, Palo Verde Road, Ajo Way, Corona Road, Valencia Road, Tucson Airport.
    • Laos Transit Center branch merged with Route 50 in 2025, to create a continuous route along Ajo Way.
    12 S. 12th Avenue Los Reales Road/Nogales Highway Ronstadt Transit Center, Downtown 12th Avenue, 10th Avenue, South Tucson, Tucson Convention Center, Downtown.
    • Merged with Route 24 to become a circular in 2025.
    15 Campbell Banner University Medical Center-Southern Campus Tohono Tadai Transit Center Roger Road, Campbell Avenue, University of Arizona, Eastland Street.
    16 Oracle/S. 6th Avenue Laos Transit Center Tohono Tadai Transit Center Downtown, Oracle Road, 6th Avenue
    • Original Route 16 was restructured in 2015, and it was split into Route 12 and Route 16. It was restructured once again in 2025, where service north of TTC was split into Route 62 and the remainder of the route was merged with Route 18.
    17 Country Club/29th St. Broadway/Houghton Park & Ride Tohono Transit Center Harrison Road, Golf Links Road, 29th Street, Country Club Road, Prince Road, Flowing Wells Rd
    19 Stone Ronstadt Transit Center, Downtown Tohono Tadai Transit Center Stone Avenue, Downtown
    21 W. Congress/Silverbell Ronstadt Transit Center, Downtown West Goret Road/Dales Crossing Drive Silverbell Road, Congress Street, Downtown.
    23 Mission Laos Transit Center Ronstadt Transit Center, Downtown Irvington Road, Mission Road, 36th Street, Silverlake Road/29th Street, 4th Avenue, South Tucson, Downtown.
      25 S. Park Avenue Tucson International Airport Ronstadt Transit Center, Downtown Downtown, Park Avenue, Irvington Road, Tucson Airport.
        26 Benson Highway Craycroft Road/Benson Highway Laos Transit Center Valencia Road, Benson Highway, Drexel Road, Campbell Avenue, Irvington Road.
          27 Midvale/Valencia Valencia Road/Camino De Oeste Laos Transit Center Valencia Road, Cardinal Avenue, Drexel Road, Midvale Park Road, Santa Clara Avenue, 12th Avenue.
          • Route 27 frequency during peak hours was reduced to every 30 minutes in 2016.
          29 Pasqua Yacui/UMC Banner South Banner University Medical Center-Southern Campus Casino del Sol, AVA Amphitheater Park & Ride 6th Avenue, Valencia Road, Los Reales Road, Tetakusim Road, Pasqua Yaqui Pueblo.
          34 Craycroft/Ft. Lowell Davis Monthan Air Force Base Visitor Center Tohono Tadai Transit Center Davis Monthan Air Force Base, Craycroft Road, East Fort Lowell Road, North Stone Avenue.
          37 Pantano Pima College (PCC) East
          Amazon (Kolb Road/Valencia Road)
          Udall Transit Station Pantano Road, Tanque Verde Road.
          • Route 37 buses do not stop on the 22nd Street segment.
          • Select trips serve Amazon at Kolb Road/Valencia Road.
          • Route 37 was restructured in 2016 to eliminate the segment north of Tanque Verde due to low demand.
          61 La Cholla Tohono Tadai Transit Center Foothills Mall Drive at La Cholla (in front of Walmart) Wetmore Road, Auto Mall Drive, La Cholla Boulevard, Ina Road, Shannon Road.
            62 Ina Road Tohono Tadai Transit Center Thornydale/Ina Roads (parking lot of Lowe's at Ina) Ina Road

            Sun Express

            Sun Trans operates 10 Sun Express routes, which offer limited-stop service on weekdays during peak commute hours.

            Current routes

            Route No. Route Name Termini Areas/corridors served
            Express Routes to and from Downtown
            101X Golf Links-Downtown Express 22nd Street/Harrison Road
            AM
            ----

            PM
            Downtown Tucson Golf Links Road, Downtown Tucson
            103X Northwest-UA Downtown Express Ina Road/Camino de las Capas
            AM
            ----

            PM
            Downtown Tucson Ina Road, Oracle Road, River Road, Campbell Avenue, Speedway Boulevard, University of Arizona, Downtown Tucson.
            105X Foothills-Downtown Express Sunrise/Kolb Roads
            AM
            ----

            PM
            Downtown Tucson Catalina Foothills, Swan Road, Speedway Boulevard, University of Arizona, Downtown Tucson.
            107X Oro Valley-Downtown Express Rancho Vistoso Park & Ride Downtown Tucson Oro Valley, Oracle Road, Downtown Tucson.
            109X Catalina Highway-Downtown Express Catalina Highway/Tanque Verde Road
            AM
            ----

            PM
            Downtown Tucson Tanque Verde Road, 5th Street, University of Arizona, Downtown Tucson.
            110X Rita Ranch-Downtown Express Downtown Tucson Old Vail Road Park & Ride Downtown Tucson, University of Arizona Science & Technology Park, Rita Ranch.
            124X Northwest-Downtown Express CDO Riverfront Park at Lambert Lane
            AM
            ----

            PM
            Downtown Tucson La Canada Drive, Ina Road, Marana, Downtown Tucson.
            Express Routes to and from Aero Park
            201X Eastside-Aero Park Express Harrison/Golf Links Roads
            AM
            ----

            PM
            Aero Park, Raytheon Tucson East side, Harrison Road, Speedway Boulevard, Alvernon Way, Palo Verde Road, Aero Park Area, Raytheon.
            203X Oro Valley-Aero Park Express Rancho Vistoso Park & Ride
            AM
            ----

            PM
            Aero Park, Raytheon Oro Valley, Laos Transit Center, Aero Park Area, Raytheon.
            204X Northwest-Aero Park Express Crossroads Park at Silverbell Road
            AM
            ----

            PM
            Aero Park, Raytheon Marana, Laos Transit Center, Aero Park Area, Raytheon.

            Sun Link

            Sun Link is a 3.9 mi (6.28 km) modern streetcar system that travels through the downtown area, connecting the main University of Arizona campus with the Mercado District on the western edge of downtown. Construction began in April 2012, with revenue service beginning in July 2014. The rolling stock is manufactured by Oregon-based United Streetcar.

            Sun Link is double-tracked, replacing a single-track configuration previously used by Old Pueblo Trolley (OPT), a volunteer-run heritage streetcar operation, begun in 1993, mainly used by tourists and local patrons (including University of Arizona students) of the numerous small shops, bars and restaurants along the line. The maintenance facility is located just west of the OPT car barn and yard on 8th Street west of 4th Avenue. OPT last ran on October 31, 2011, when service was suspended for Sun Link construction; the plan was for Old Pueblo Trolley to share operations, trackage and stations with Sun Link, but no date has yet been set for OPT service to resume.

            Sun Shuttle

            Sun Tran operates 10 Sun Shuttle routes, which connect outlying neighborhoods to Sun Tran and Sun Express service. As of 2024, service in Ajo is operated by Ajo Transportation.

            Sun Van

            Sun Van is a paratransit service that offers alternative transportation for riders that are unable to use fixed-route buses because of a disability. Trips must be reserved 1-7 days in advance. In 2022, Sun Tran launched an app that allows riders to track their reserved shuttle in real time.

            03Fares

            All fares have been free since March 2020. Previously, the base fare was $1.75 and reduced fare was $0.75. The express bus fare was $2.35. No fares had applied to kids under 6 with fare-paying rider, limit 3. All fares used to be paid with a SunGo smart card, which can be loaded with cash value or passes. 24-hour passes & 30-day tickets were available. The University of Arizona provided discounted passes for eligible students, faculty and staff through the UA's Parking and Transportation Services.

            A Sun Link streetcar on Congress Street in 2014
            A Sun Link streetcar on Congress Street in 2014

            04Fleet

            Sun Tran has an active fleet of 126 buses. In 2008, Sun Tran signed a contract with Gillig to purchase 119 biodiesel buses. This was done to avoid the need to expand CNG fueling capacity at its depot. However, Sun Tran plans to replace all diesel buses with CNG buses by FY26.

            Current fleet
            Image Builder and Model Year Length Fuel Number(s) Quantity Notes
            Gillig Low Floor 2006 40' B5 Biodiesel 2601-2612 12 These buses have a different seating configuration compared to the 2005 Gillig buses, as seats are all arranged lengthwise (except for the last row of seats). This was done to reduce vandalism that has been caused to bus windows and the interior.
            Gillig Low Floor BRT 2008-2009 40' B5 Biodiesel 2901-2936 36 These buses, labeled "Sun Express", are used on express routes 101X-312X, and occasionally as shuttles for special events. Features include head rests, reclining seats, and heat resistant windows.
            Gillig Low Floor 2009 40' B5 Biodiesel 2937-2950, 3001-3010 14 The 29XX buses (known as transition buses) are Low Floor, not BRT, and feature head rests and reclining seats. The rest (3001-3010) are regular Low Floor buses.
            2009 40' B5 Biodiesel-Electric Hybrid 3000 1 First hybrid bus introduced in 2010. It featured a promotional livery until 2014 when it was painted with the same livery as the other regular buses.
            2011-2012 40' B5 Biodiesel-Urea 3011, 3101-3156 57 These buses run with a blend of Biodiesel-5% Urea.
            2012 40' B5 Biodiesel-Electric Hybrid 4001-4010 10 New hybrid buses placed in service at the end of December 2012.
            2014 40' CNG 3201-3224 24 The majority of the buses will go into service by the end of August. These new buses will eventually replace the 14-year-old Nova buses.
            2014 35' CNG 3225-3229 4 These new CNG buses are smaller (35-foot-long compared to the standard 40 feet) and have a total of 30 seats. These will replace the 14-year-old Nova buses.
            2014 40' CNG 3230-3245 16 New CNG buses placed in service to replace the old CNG buses.
            2018 40' CNG 3301-3323 23
            2020 40' CNG 3401-3420 20
            2022 40' CNG 3501-3518 18
            2020 40' CNG 4011 1 This is a 2019 model
            2021 40' 4012-4016 5
            2022 40' 4017-4021 5
            Watch videos about Sun TranExplainers and documentaries on YouTube (opens in a new tab)

            Sources and credits

            This article is adapted from the Wikipedia article Sun Tran, written by its contributors and licensed under CC BY-SA 4.0. Fathomly has changed the layout, removed citation markers, navigation and maintenance notices, and adjusted punctuation. This adapted version is shared under the same license. For references, see the original article.

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