# Sun Tran

Sun Tran is the public transit system serving the city of Tucson, Arizona. In 2023, the system had 17,361,800 rides, or about 59,500 per weekday as of the third quarter of 2024. 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.

## History

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.
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.
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.

## Awards

Sun Tran won the America's Best Transit System award for 1988 and 2005 from the American Public Transportation Association in the category of 4 to 30 million annual passenger trips. Also, Sun Tran was awarded as the Arizona's Best Transit System for 2004 and 2012.

## Fares

NOTE: all fares are free since late March 2020 ever since the COVID-19 outbreak.
The basic rate is free to all. Previously, it was $1.75; reduced fare for low-income, persons with disabilities, seniors at least 65 and Medicare cardholders was $0.75 (with a valid SunGO ID & card). The express bus fare was $2.35. No fares apply to kids under 6 with fare-paying rider, limit 3. All fares used to be paid with a SunGo card, which utilised smart card technology, and can be loaded with cash value or passes. 24-hour passes ($4) & 30-day tickets ($48) were available. The University of Arizona provided discounted passes for eligible students, faculty and staff through the UA's Parking and Transportation Services.

## Fleet
### Current fleet

Sun Tran has an active fleet of 237 buses.
| Builder | Model | Year | Length | Engine/ Transmission | Fuel | Number(s) | Quantity | Notes |
| Gillig | G20D102N4 Low Floor | 2006 | 40' | Cummins ISM Allison B400R5 Gen-III | 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 | G20D102N4 Low Floor BRT | 2008-09 | 40' | Caterpillar C9 ACERT 9.3L ZF Ecomat 4 6HP594C | B5 Biodiesel | 2901-2936 | 46 | These buses, labeled "Sun Express", are used on express routes 101X-312X, and occasionally as shuttles for special events. Features include low floor, head rests, reclining seats, and heat resistant windows. |
| Gillig | G20D102N4 Low Floor | 2009 | 40' | Cummins ISL 8.9L Allison B400R5 Gen-IV | 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. |
| Gillig | G20D102N4 Low Floor | 2009 | 40' | Cummins ISL Allison E$^P$40 Gen-IV Hybrid System | 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. This bus is run on route 5, which runs between the intersection of Sabino Canyon and Tanque Verde roads and the Pima Community College West Campus. |
| Gillig | G20D102N4 Low Floor | 2011 | 40' | Cummins ISL9 Allison B400R6 Gen-IV | B5 Biodiesel-Urea | 3011, 3101-3119 | 20 | These buses run with a blend of Biodiesel-5% Urea. |
| Gillig | G20D102N4 Low Floor | 2012 | 40' | Cummins ISL9 Allison B400R6 Gen-V | B5 Biodiesel-Urea | 3120-3156 | 37 | Similar to Gillig 2011 buses. |
| Gillig | G20D102N4 Low Floor | 2012 | 40' | Cummins ISL9 Allison H 40 EP Gen-V Hybrid System | B5 Biodiesel-Electric Hybrid | 4001-4010 | 10 | New hybrid buses placed in service at the end of December 2012. |
| Gillig | G20D102N4 Low Floor | 2014 | 40' | Cummins ISL G Allison B400R Transmission | 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. |
| Gillig | G20D102N4 Low Floor | 2014 | 35' | Cummins ISL G Allison B400R Transmission | 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. |
| Gillig | G20D102N4 Low Floor | 2014 | 40' | Cummins ISL G Allison B400R Transmission | CNG | 3230-3245 | 16 | New CNG buses placed in service to replace the old CNG buses. |
| Gillig | G20D102N4 Low Floor | 2018 | 40' | Cummins L9N Allison B400R Transmission | CNG | 3301-3323 | 23 | |
| Gillig | G20D102N4 Low Floor | 2020 | 40' | Cummins L9N Allison B400R Transmission | CNG | 3401-3420 | 20 | |
| Gillig | G20D102N4 Low Floor | 2022 | 40' | Cummins L9N Allison B400R Transmission | CNG | 3501-3518 | 18 | |
| Gillig | G20D102N4 Low Floor | 2020 | 40' | Cummins L9N Allison B400R Transmission | CNG | 4011 | 1 | This is a 2019 model |
| Gillig | G20D102N4 Low Floor | 2021 | 40' | | | 4012-4016 | 5 | |
| Gillig | G20D102N4 Low Floor | 2022 | 40' | | | 4017-4021 | 5 | |

### Retired Fleet

Note that this is by no means a complete listing of retired vehicles that have operated for Sun Tran and/or its predecessors.
| Builder | Model | Year | Length | Fuel | Number(s) | Quantity | Notes |
| Yellow Coach | Model 733 | 1937 | 30' | Gasoline | 14-15 | 2 | These buses were withdrawn after World War II. The engine was located in the front and they sat 21 passengers. |
| Yellow Coach | Model 733 | 1938 | 30' | Gasoline | 16-17 | 2 | These buses were identical to the 1937 Model 733 buses. |
| Yellow Coach | Model 1204 | 1939 | 30' | Gasoline | 18-22 | 5 | These buses had a rear engine and sat 24 passengers. |
| Yellow Coach | Model 1204 | 1940 | 30' | Gasoline | 23-26 | 4 | These buses were identical to the 1939 Model 1204s. |
| Ford | Model 69B | 1941 | 30' | Gasoline | 27-31 | 5 | These buses were built for World War II. |
| Ford | Model 69B | 1942 | 30' | Gasoline | 32-36 | 5 | These buses were built for World War II. |
| Ford | Model 69B | 1943 | 30' | Gasoline | 37-41 | 5 | These buses were built for World War II. |
| Ford | Model 69B | 1944 | 30' | Gasoline | 42-46 | 5 | These buses were built for World War II. |
| Ford | Model 69B | 1945 | 30' | Gasoline | 47-49 | 3 | These buses were built for World War II. |
| Ford | Model 69B | 1946 | 30' | Gasoline | 50-55 | 6 | These buses were withdrawn from service in 1955. |
| Twin Coach | 41-S "Art Deco" | 1946 | 35' | Gasoline | 101-106 | 6 | These buses were some of the earliest to operate in Tucson. All were withdrawn in 1968. |
| Twin Coach | 41-S "Art Deco" | 1947 | 35' | Gasoline | 107-112 | 6 | These buses were identical to the 1946 Twin Coach buses. |
| Twin Coach | 34-S "Art Deco" | 1948 | 30' | Gasoline | 113-115 | 3 | These buses were withdrawn in the late-1960s. Some were converted to school buses before that. |
| GMC | TDH-4509 "Old Look" | 1951 | 35' | Diesel | 201-206 | 6 | These buses were retrofitted with A/C in the late-1950s. They were withdrawn from service in the 1970s. |
| GMC | TGH-3101 "Old Look" | 1951 | 30' | Gasoline | 121-126 | 6 | These buses were operated by the Old Pueblo Transit Company, which was the transit agency for South Tucson. |
| GMC | TDH-4509 "Old Look" | 1952 | 35' | Diesel | 207-215 | 9 | These buses were similar to the 1951 TDH-4509 buses. All were withdrawn in the 1970s. |
| GMC | TGH-3101 "Old Look" | 1952 | 30' | Gasoline | 127-129 | 3 | These buses were operated by the Old Pueblo Transit Company and were withdrawn in the 1960s. |
| GMC | TDH-4512 "Old Look" | 1953 | 35' | Diesel | 216-218 | 3 | These buses were retrofitted with A/C in the late-1950s. |
| GMC | TGH-3102 "Old Look" | 1953 | 30' | Gasoline | 130 | 1 | This bus was operated by the Old Pueblo Transit Company. |
| GMC | TDH-4512 "Old Look" | 1957 | 35' | Diesel | 220-222 | 3 | These buses were retrofitted with A/C in the late-1950s. |
| GMC | TDH-4512 "Old Look" | 1959 | 35' | Diesel | 223-225 | 3 | These buses were retrofitted with A/C in the early-1960s. |
| GMC | TGH-3102 "Old Look" | 1959 | 30' | Gasoline | 131-133 | 3 | These buses were operated by the Old Pueblo Transit Company and were withdrawn in the 1970s. |
| GMC | TGH-3102 "Old Look" | 1960 | 30' | Gasoline | 134-136 | 3 | These buses were similar to the 1949 TGH-3102 buses but only had a single door. They were withdrawn from service in 1974. |
| GMC | TDH-4517 "New Look" | 1962 | 35' | Diesel | 228-231 | 4 | These buses were the first in Tucson to be built with air conditioning, and were also the first GMC "New Look" buses in service. They were withdrawn from service in the early 1980s. |
| GMC | TDH-3501 "Old Look" | 1966 | 30' | Diesel | 140 | 1 | Although this bus was built in 1966, it had the "Old Look" design. It was built for Old Pueblo Transit Company and withdrawn from service in the late-1970s. |
| GMC | T6H-4523A "New Look" | 1972 | 35' | Diesel | 7201-7211 | 11 | These buses were the first to be ordered by the city of Tucson. |
| GMC | T6H-4523A "New Look" | 1973 | 35' | Diesel | 7312-7321 | 10 | These buses were identical to the 1972 GMC New Looks. |
| Flxible | 45096 "New Look" | 1973 | 35' | Diesel | 7322-7331 | 10 | These buses were the first Flxible buses to enter service in Tucson. They were withdrawn from service in the 1990s. |
| GMC | T6H-4523A "New Look" | 1974 | 35' | Diesel | 7402-7403 | 2 | These buses were ordered by an operator in Texas but ended up in service in Tucson. They were renumbered from 1402 to 1403 and were withdrawn from service in the mid-1990s. |
| GMC | T8H-5307A "New Look" | 1974 | 40' | Diesel | 1474-1479, 1481, 1484, 1488 | 9 | These buses were delivered new to Tucson but were actually built for various transit agencies across the United States who did not take up these buses. They were temporarily operated in Tucson from 1974 to 1978, when they were replaced with AM General buses. 1475-1478 were sold to Valley Metro and were withdrawn in 1989, while the rest were sent to other operators. These were the first 40-foot-long (12 m) buses in Tucson. |
| Flxible | 45096 "New Look" | 1975 | 35' | Diesel | 7532-7563 | 32 | These buses were the first to be built for Sun Tran (along with the 1975 AM General 9640-8 buses) and featured a different livery from the red and yellow that is featured on buses today. All of these buses were withdrawn in the mid-1990s. |
| AM General | 9640-8 "Metropolitan" | 1975 | 40' | Diesel | 5501-5512 | 12 | These buses were the first to be built for Sun Tran (along with the 1975 Flxible 45096 buses), and featured a different livery from the red and yellow that is featured on buses today. All of these buses were withdrawn in the mid-1990s. |
| Flxible | 35096 "New Look" | 1976 | 30' | Diesel | 7664-7684 | 21 | These buses were built for Old Pueblo Transit, which served the city of South Tucson. Originally, these buses were numbered 5050-5070 but after OPT was taken over by Sun Tran in 1978, these buses were renumbered to 7664–7684. All of these buses were withdrawn in the mid-1990s. |
| AM General | 10235B "Metropolitan" | 1977 | 35' | Diesel | 7764-7775 | 12 | These buses were all withdrawn by 1997. |
| AM General | 10240B "Metropolitan" | 1978 | 40' | Diesel | 5713-5724 | 12 | These were the first buses painted in the red and yellow Sun Tran livery. All of these buses were withdrawn by 1997. |
| GMC | T8J-204 "RTS-04" | 1981 | 40' | Diesel | 8101-8119 | 19 | These were Tucson's first RTS buses. They featured rollsigns and frameless windows. All were withdrawn from service in 2000. |
| GMC | T8J-204 "RTS-04" | 1986 | 40' | Diesel | 8601-8613 | 13 | All of these buses were withdrawn from service in 2000. |
| GMC | T8J-206 "RTS-06" | 1986 | 40' | Diesel | 8614-8629 | 16 | These buses were similar to the earlier 1986 GMC buses but were built as RTS-06 models rather than RTS-04 models. All were withdrawn from service in 2000. |
| Orion Bus Industries | 02.501 | 1994 | 25' | CNG | 9470-9475 | 6 | These buses were powered by CNG and were withdrawn in the early 2000s. |
| TMC | T80-206 "RTS-06" | 1989 | 40' | Biodiesel | 8930-8984 | 55 | Only 8 buses of various numbers remained in the fleet until May 2008 were mostly used on express routes. Most of this type was retired in the fall of 2005 with the arrival of the 2005 Gilligs. These buses were formerly powered by diesel. |
| Neoplan USA | AN440 | 1991 | 40' | Biodiesel | 9101-9125 | 25 | 9123-9125 formerly ran on Diesel/CNG |
| Neoplan USA | AN440 | 1993 | 40' | Biodiesel | 9326-9340 | 15 | These buses were formerly dual-fueled and could run on diesel or CNG. They are identical to the 1991 Neoplan buses. |
| Neoplan USA | AN440 | 1994 | 40' | Biodiesel | 9441-9469 | 29 | These buses were formerly dual-fueled and could run on diesel or CNG. They have Luminator Mega:MAX flip-dot signs and a different A/C unit compared to the other Neoplan buses. The last ones in service were retired from the active fleet in 2012 with the arrival of the new 2012 Gilligs. |
| New Flyer | C40HF | 1996 | 40' | CNG | 9676-9694 | 19 | These buses were the first purely CNG-powered buses in the Sun Tran fleet. They also were the first buses to feature automatic stop announcements and hard seats throughout the entire bus (rather than just in the rear). These were withdrawn in 2011 when the new Gillig 2011 buses arrived. |
| New Flyer | C40HF | 1997 | 40' | CNG | 9701-9725 | 25 | These buses are similar to the 1996 New Flyer buses but feature grey interior flooring and sidewalls rather than the orange interior found on the 1996 buses. Retired in Fall 2012 with the arrival of the 2012 Gillig buses. |
| Nova Bus | 40102CNG "RTS-WFD" | 2000 | 40' | CNG | 2001-2045 | 16 | These buses originally featured Luminator LEDot front signs, but they were replaced with Luminator Horizon signs in 2005. 24 of these buses were retired from the active fleet in July 2014. The other were withdrawn in 2015. |

## Current Routes

Sun Tran operates 29 regular routes and 13 express routes, as well as 10 Sun Shuttle routes, a neighborhood transit service. Most regular routes provide service from 6 am to 11 pm. A few routes provide service until midnight. Sun Tran does not provide overnight service.

### Regular Routes

| Route No. | Route Name | Termini | Termini | Termini | Major Streets/Areas Serviced | Service Notes/History |
| 1 | Glenn/Swan | Ronstadt Transit Center, Downtown | ↔ | Swan Road/29th Street | Downtown, Main Gate Square, University of Arizona, Park Avenue, Glenn Street, Swan Road. | Weekday service operates every 30 minutes (60 minutes at night). Weekend service every hour. Route was restructured in 2015 and service on 29th St was eliminated. |
| 2 | Pueblo Gardens | Laos Transit Center | ↔ | Ronstadt Transit Center, Downtown | Irvington Road, Country Club Road, Campbell Avenue, 36th Street, Pueblo Gardens, Downtown. | Weekday service operates every 30 minutes (60 minutes at night). Weekend service every hour. |
| 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. | Weekday service operates every 30 minutes, 60 minutes at night. 20 minutes peak-hour service during weekdays, with extra buses (plugs) available to alleviate overcrowding issues. Weekend service every hour. |
| 4 | Speedway | Broadway/Houghton Park & Ride (1st segment) Golf Links/Kolb Park & Ride (2nd segment) | ↔ | Ronstadt Transit Center, Downtown | Speedway Boulevard, Harrison Road, Kolb Road, University of Arizona, Downtown. | Weekday service operates every 15–30 minutes until noon and from 6:00 pm – 7:00 pm; 10–20 minutes from noon – 6:00 pm. Weeknight and weekend service frequency is 30–60 minutes. |
| 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. | Weekday service operates every 30 minutes until 7:30 pm. Weekend service every hour. |
| 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. | Weekday service operates every 15 minutes from 6:00 am to 6:00 pm. Weeknight service every 30–60 minutes. Saturday service every 30 minutes. Sunday service runs every hour. 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 | Weekday service operates every 15 minutes from 6:00 am – 6:00 pm, and every 30 minutes from 6:00 pm – 7:30 pm. Weeknight service every 60 minutes until 11:30 pm. Weekend service every hour. |
| 8 | Broadway | Ronstadt Transit Center, Downtown | ↔ | Broadway/Houghton Park & Ride (1st segment) Udall Station at Tanque Verde/Sabino Canyon (2nd segment) | Downtown, Broadway Boulevard, Wilmot Road, Tanque Verde Road. | Weekday service operates every 15–30 minutes from the start of the service until about 11:30 am, and from 5:00 pm to 7:00 pm. Weekday frequency increases to 10–20 minutes from 11:30 am until 4:30 pm. Weeknight service every 30 minutes until midnight (no service to Wilmot/Tanque Verde after about 7:00 pm). Saturday service every 15–30 minutes. Sunday service every 20–40 minutes. Original Route 8 was restructured in 2015 and was split into Route 8 and Route 18. |
| 9 | Grant | Udall Transit Station | ↔ | Pima Community College (PCC) West | Grant Road | Weekday service operates every 15 minutes from 6:30 am – 6:30 pm; every 30 minutes from 5:00 am – 6:30 am, and from 6:30 pm – 8:00 pm. Weeknight service runs every hour. Weekend service every hour. Route 9 was merged with the former Route 20 in 2016, to create a continuous route on Grant Road. Its frequency was increased to 15 minutes from 6:30 am – 6:30 pm. Route 9 no longer services the University of Arizona and Downtown. |
| 10 | Ruthrauff | Davis Avenue/Ruthrauff Rd | ↔ | Ronstadt Transit Center, Downtown | Ruthrauff Rd, Romero Rd, River Road, Miracle Mile, Oracle Road, Downtown. | Weekday service operates every 30–60 minutes until 11:30 pm. Weekend service every hour. |
| 11 | Alvernon | Laos Transit Center (1st segment) Tucson International Airport (2nd segment) | ↔ | Dodge Boulevard/River Road | Alvernon Way, Palo Verde Road, Ajo Way, Corona Road, Valencia Road, Tucson Airport. | Weekday service operates every 15 minutes north of Ajo Way, and 30 minutes frequency on both south segments (Ajo Way/Laos Center and Palo Verde/Tucson Airport). Weeknight service frequency is 30–60 minutes after 7:00 pm until 12:20 am. Alternated night service to/from the Tucson airport after 7:00 pm. Service every 30–60 minutes during weekends. |
| 12 | 10th/12th Avenue | Laos Transit Center | ↔ | Ronstadt Transit Center, Downtown | 12th Avenue, 10th Avenue, South Tucson, Tucson Convention Center, Downtown. | Weekday service operates every 15 minutes between 6:00 am and 6:30 pm. Weeknight service frequency is 30 minutes. Weekend service every 30 minutes. |
| 15 | Campbell | Banner University Medical Center-Southern Campus | ↔ | Tohono Tadai Transit Center | Roger Road, Campbell Avenue, University of Arizona, Eastland Street. | Weekday service operates every 15 minutes from the start of the service until 6:00 pm. Weeknight service frequency is 30–60 minutes after 6:00 pm until 11:30 pm. Weekend service every hour. |
| 16 | Oracle/Ina | Ronstadt Transit Center, Downtown | ↔ | Thornydale/Ina roads (parking lot of Lowe's at Ina) | Downtown, Oracle Road, Ina Road. | Weekday service operates every 10 minutes between Ronstadt and Tohono (TTC) transit centers. Frequency increased to 7.5 minutes during the afternoon peak hours. Weekday frequency every 30 minutes north of Tohono Center, increased to every 15–20 minutes in the afternoon peak hours. Weeknight service every 30–60 minutes until midnight. Service frequency during weekends is 15 minutes (60 minutes north of TTC) on Saturdays, and 20 minutes (60 minutes north of TTC) on Sundays. Original Route 16 was restructured in 2015, and it was split into Route 12 and Route 16. |
| 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 | Weekday service operates every 30–60 minutes until 11:00 pm. Weekend service every hour. |
| 18 | S. 6th Avenue | Laos Transit Center | ↔ | Ronstadt Transit Center, Downtown | Downtown, South Tucson, 6th Avenue. | Weekday service operates every 15 minutes before 8:00 am and from 6:00 pm to 7:00 pm. Weekday frequency increased to 7–10 minutes from 8:00 am to 6:00 pm. Weeknight service frequency is 30 minutes after 7:00 pm until 12:30 am. Weekend service operates every 15 minutes on Saturdays and 20 minutes on Sundays. |
| 19 | Stone | Ronstadt Transit Center, Downtown | ↔ | Tohono Tadai Transit Center | Stone Avenue, Downtown | Weekday service operates every 30–60 minutes until 11:00 pm. Saturday service every 30 minutes. Sunday service every hour. |
| 21 | W. Congress/Silverbell | Ronstadt Transit Center, Downtown | ↔ | West Goret Road/Dales Crossing Drive | Silverbell Road, Congress Street, Downtown. | Weekday service operates every 30–60 minutes until 11:00 pm. Weekend service every 30 minutes. |
| 22 | Grande | Ronstadt Transit Center, Downtown | ↔ | Grant/Silverbell roads | Downtown, Congress Street, Bonita Avenue, Commerce Park Loop, Grande Avenue, Riverview Boulevard, El Rio Drive. | Weekday service operates every 30–60 minutes until 11:00 pm. Weekend service every hour. |
| 23 | Mission | Laos Transit Center | ↔ | Ronstadt Transit Center, Downtown | Irvington Road, Mission Road, 36th Street, Silverlake Road/29th Street, 4th Avenue, South Tucson, Downtown. | Weekday service operates every 30–60 minutes until 11:00 pm. Weekend service every hour. |
| 24 | 12th Avenue | Laos Transit Center | ↔ | Laos Transit Center | 12th Avenue, Los Reales Road. | Weekday service operates every 30–60 minutes until 9:20 pm. Weekend service every hour. |
| 25 | S. Park Avenue | Tucson International Airport | ↔ | Ronstadt Transit Center, Downtown | Downtown, Park Avenue, Irvington Road, Tucson Airport. | Weekday service operates every 30 minutes. Weeknight service frequency is 60 minutes until 11:55 pm. Weekend service: every 30 minutes on Saturdays (60 minutes south of Laos Center), and every 60 minutes on Sundays. |
| 26 | Benson Highway | Craycroft Road/Benson Highway | ↔ | Laos Transit Center | Valencia Road, Benson Highway, Drexel Road, Campbell Avenue, Irvington Road. | Weekday service operates every 30–60 minutes until 11:30 pm. Weekend service every hour. |
| 27 | Midvale Park | Casino del Sol, AVA Amphitheater Park & Ride | ↔ | Laos Transit Center | Valencia Road, Cardinal Avenue, Drexel Road, Midvale Park Road, Santa Clara Avenue, 12th Avenue. | Weekday service operates every 30–60 minutes until 11:00 pm. Weekend service every hour. Route 27 frequency during peak hours was reduced to every 30 minutes in 2016. |
| 29 | Valencia | Laos Transit Center | ↔ | Casino del Sol, AVA Amphitheater Park & Ride | 6th Avenue, Valencia Road, Los Reales Road, Tetakusim Road, Pasqua Yaqui Pueblo. | Weekday service operates every 30–60 minutes until 11:30 pm. Weekend service every hour. |
| 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. | Weekday service operates every 15 minutes from 6:00 am – 6:00 pm. Service every 30–60 minutes until 11:30 pm. Weekend service every hour. |
| 37 | Pantano | Pima College (PCC) East | ↔ | Udall Transit Station | Pantano Road, Tanque Verde Road. | Route 37 buses do not stop on the 22nd Street segment. Weekday service operates every 30 minutes until 7:45 pm. Weekend service every hour. Route 37 was restructured in 2016 to eliminate the segment north of Tanque Verde due to low demand. |
| 50 | Ajo Way | Laos Transit Center | ↔ | Ajo Way/Mission Road | Ajo Way, 6th Avenue. | Weekday service operates every 30–60 minutes until 9:30 pm. Weekend service every hour. |
| 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. | Weekday service operates every 30 minutes until 8:00 pm. Weekend service every hour. |

### Express Routes

| Route No. | Route Name | Termini | Termini | 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 |
| 102X | Northwest-UA Express | CDO Riverfront Park at Lambert Lane | → AM ---- ← PM | Banner-University Medical Center | La Canada Drive, Ina Road, Downtown Tucson, Speedway Boulevard, University of Arizona. |
| 103X | Northwest-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. |
| 104X | Marana-Downtown Express | Crossroads Park at Silverbell Road | → AM ---- ← PM | Downtown Tucson | Marana, 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. |
| 108X | Broadway-Downtown Express | Broadway/Houghton Park & Ride | → AM ---- ← PM | Downtown Tucson | Broadway Boulevard, 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. |
| 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. |

## Alternative propulsion

For at least the next five years, Sun Tran will use more biodiesel buses. Biodiesel is a cleaner than regular diesel. Sun Tran plans to buy an additional 119 biodiesel buses over its five-year contract with bus manufacturer Gillig Corp. buses are also capable of running on regular diesel, but Sun Tran does not use petrodiesel in any of its buses. Sun Tran uses B20 and B5 biodiesel blends in its 114 biodiesel buses. It is believed that the increased use of biodiesel avoided a potential fare increase and fuel surcharge in July 2008.

## Customer service

Sun Tran publishes a transit book, known as the Ride Guide, and it is updated twice yearly, on February and on August. It contains maps and schedules for all regular and express routes. Copies are available at multiple locations around town, including the Sun Tran offices, many public libraries, community colleges, major malls, pass sales outlets, at other civic facilities around the metropolitan area, and on the buses themselves. The Ride Guide is also available online at the Sun Tran website. Additionally, route schedules are posted at the transit centers in the City of Tucson.
A customer service call center is operated for passengers to plan their bus trips with the assistance of a live customer service representative, information for Sun Tran, Sun Express, Sun Shuttle and Sun Link, fares and SunGO information, detours, comments and questions. The Sun Tran website also has an online trip planning function, and includes all schedules and maps featured in the Ride Guide.

## Regional Transportation Plan and streetcar system

In May 2006, voters in Tucson approved a Regional Transportation Plan (a comprehensive bus transit/streetcar/roadway improvement program), and its funding via a new 20-year half-cent sales tax increment. The centerpiece of the Regional Transportation Plan is Sun Link, a 3.9 mi (6.28 km) modern streetcar system (inspired by the successful Portland Streetcar in Oregon) that travels through the downtown area, connecting the main University of Arizona campus with the Mercado District master plan area (known at that time as Rio Nuevo) on the western edge of downtown.
In December 2010, a $63 million federal TIGER grant was awarded to the City of Tucson, meeting most of a remaining funding gap and allowing the modern streetcar project to move forward. An additional $6 million of federal funding was obtained through the Federal Transit Administration's New Starts program. Funding also came from utilities for relocation and improvements along the streetcar route, most significantly $10.6 million from Tucson Water.
The Sun Link name was officially announced in the spring of 2012. Construction began in April 2012, with revenue service beginning in July 2014.
Oregon-based United Streetcar manufactured the Sun Link vehicles. Sun Link maintains a fleet of eight vehicles, using up to six cars at once. Tucson placed an initial $26 million order for seven cars in June 2010. The eighth car was ordered for an additional $3.6 million in July 2012 in order to satisfy FTA requirements for a second spare. United's first model 200 car arrived in Tucson by flatbed truck on August 30, 2013.
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.

## Regional seamless transit system

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 that extends across not only the Sun Tran buses, but the other services as well (even the renderings and computer animations of the then-under-development Sun Link streetcar were converted to the new design). 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. Current vehicles will keep their existing liveries until they are either overhauled or replaced. Also in the works are new fare machines that allow a single "smart card" to pay fares on Sun Tran, Sun Express, Sun Connect, and the downtown streetcar; and improved signage at bus stops and transit centers.
Sun Connect service started on May 4, 2009, under the name Sun Shuttle, with routes to the north and northwest, Green Valley, and Sahuarita.