Arizona

Sun Link, also known as the Tucson Streetcar, is a single-line streetcar system in Tucson, Arizona, United States, that began service in July 2014. The system's 3.9-mile (6.3 km) route connects the Arizona Health Sciences Center (including University Medical Center), the University of Arizona campus, the Main Gate and 4th Avenue shopping and entertainment districts, downtown Tucson, the Tucson Convention Center, and the Mercado District under development west of Interstate 10. The streetcar project's overall cost of $196 million was met through a combination of local funding sources and federal grants. The streetcar shares a common payment system with the Sun Tran regional bus service. In 2024, the line had a ridership of 1,676,500, or about 4,400 per weekday as of the second quarter of 2025.

Cycling is popular in Tucson. Tucson and Pima County maintain an extensive network of marked bike routes, signal crossings, on-street bike lanes, mountain-biking trails, and dedicated shared-use paths. The Loop is a network of seven linear parks, built mainly along river beds, comprising 131 miles (211 km) of paved, vehicle-free trails that encircles the majority of the city with links to Marana and Oro Valley. The Tucson–Pima County Bicycle Advisory Committee (TPCBAC) serves in an advisory capacity to local governments on issues relating to bicycle recreation, transportation, and safety. The League of American Bicyclists awarded Tucson a gold rating for bicycle-friendliness in 2006.

Arizona is a landlocked state in the Southwestern region of the United States, sharing the Four Corners region of the western United States with Colorado, New Mexico, and Utah. It also borders Nevada to the northwest and California to the west, and shares an international border with the Mexican states of Sonora and Baja California to the south and southwest. Its capital and largest city is Phoenix, which is the most populous state capital and fifth-most populous city in the United States. Arizona is divided into 15 counties.