[citation needed] In December 2010, a $63 million federal TIGER grant was awarded to the City of Tucson, meeting most of the remaining funding gap and allowing the project to move forward.

[10] A 320-foot (98 m) bridge across the Santa Cruz serving streetcar, automobile, bicycle, and pedestrian traffic was constructed in 2012 under a separate contract.

[18] Construction of the Sun Link Operations & Maintenance Facility, an $8 million depot centered on the system route at 5th Avenue and 8th Street, began in May 2012.

[22] The United 200 is largely identical to the 100 model produced for systems in Portland and Washington, D.C., the only major difference being that the 200 is equipped with upgraded air-conditioning.

[22] The design of the 100 model itself is based on the Czech-made Škoda 10 T.[23] Tucson placed a $26 million order with United for seven cars in June 2010.

[29] Half-hour late-night service provided only while the University of Arizona is in session runs through 2am on Thursday, Friday, and Saturday nights.

[32] Previously a SunGO pass or fare card, available at the Ronstadt Transit Center, online, and at various retail locations, must have been purchased prior to boarding; payment was not accepted by Sun Link drivers.

24-hour passes used to be available for $4.50 from ticket vending machines located on all Sun Link platforms, payable either in exact change or by credit.

[13] North of the Warren Avenue stop, the streetcar passes under Speedway Boulevard on a single-track line in a dedicated right of way.