Fourth Avenue Underpass Southbound Lane Closure: Amended Start Time for Detour

The City of Tucson Department of Transportation (TDOT) will again close the southbound travel lane through the Fourth Avenue Underpass at Ninth Street. Last week’s traffic control change significantly decreased the gridlock at the Congress Street/Toole Avenue/Fourth Avenue intersection. Please note that the northbound travel lane through the underpass will remain open to all modes of travel. 

The southbound lane closure will take place on Thursday, August 28, Friday, August 29 and Saturday, August 30 from 9 p.m. to 2 a.m. 

During the closure, the Sun Link Streetcar and bicyclists will be allowed to use the southbound travel lane through the underpass, and pedestrians will be allowed to use the southbound sidewalk through the underpass. Motorists will be detoured at Ninth Street west to Stevens Avenue, north on Fifth Avenue to Seventh Street. Motorists can then travel south on Sixth Avenue to access Downtown.

Eastbound travel on Ninth Street at Fourth Avenue will be restricted to “local traffic only” to lessen the traffic impacts to the adjacent neighborhood. Business access signs will be in place to inform motorists that businesses along Ninth Street remain open.

For the past several weeks, TDOT staff has been evaluating and monitoring traffic volumes, traffic movements and pedestrian access at the Congress Street, Fourth Avenue and Toole Avenue intersection. The increased activity in the downtown area, specifically at the Congress/Fourth/Toole intersection, has caused vehicular gridlock conditions. TDOT staff made permanent traffic signal timing adjustments last week on Congress which improved traffic flows.  

Electronic message boards will be in place along Fourth Avenue to inform motorists of this weekend’s travel lane restriction. Motorists are urged to use caution when traveling along Fourth Avenue and in the downtown area due to the high volume of pedestrian activity in these entertainment districts.