Sun Tran
Public transit system serving Tucson, Arizona

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.

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. |
|
| 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. |
|
| 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. |
|
| 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 |
|
| 9 | Grant | Pima Community College (PCC) West | ↔ | Pima Community College (PCC) West | Grant Road, Kolb Road |
|
| 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. |
|
| 12 | S. 12th Avenue | Los Reales Road/Nogales Highway | ↔ | Ronstadt Transit Center, Downtown | 12th Avenue, 10th Avenue, South Tucson, Tucson Convention Center, Downtown. |
|
| 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 |
|
| 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. |
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| 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. |
|
| 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. |
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| 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.

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.
| 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 |
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.
Images, from Wikimedia Commons:
- Tucson May 2019 32 (Sun Tran bus).jpg by Michael Barera, CC BY-SA 4.0
- Tucson May 2019 26 (Ronstadt Transit Center).jpg by Michael Barera, CC BY-SA 4.0
- Tucson Sun Link streetcar at 5th & Congress (2014).jpg by David Wilson from Oak Park, Illinois, USA, CC BY 2.0
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