S. 12th Ave Project Performance Study
Published on August 27, 2025
In October 2020, the City of Tucson Department of Transportation and Mobility (DTM) reconfigured S. 12th Avenue between Irvington Road and Drexel Road from five lanes to three lanes, one lane in each direction and a center turn lane. The project also added on-street parking and enhanced bike lanes to improve safety and accessibility for all users. The University of Arizona’s Center for Applied Transportation Sciences has conducted a before-and-after study of the project and found improvements in key safety metrics such as total crashes and traffic-related fatalities following the improvements.
During the before period, studied between 2017 and 2019, two traffic-related fatalities occurred on S. 12th Avenue between Irvington Road and Drexel Road, while zero occurred during the after study period, between 2021 and 2023, leading to a 100 percent reduction in fatalities following the implementation of the safety elements.
The study also saw a significant reduction in traffic crashes following the reconfiguration. The safety study showed a 44 percent reduction in total crashes, an 84 percent reduction in pedestrian-involved crashes, and a 100 percent reduction in bicyclist-involved crashes. Vehicle speeds also became more consistent, which contributed to a safer roadway.
As part of the study, peak travel time was also observed along this project segment. It was documented that minimal impacts to travel time occurred with the roadway reconfiguration. There was an 8.7 percent decrease in travel time northbound, and a 4 percent increase in travel time southbound.
In September, construction will begin to add green storm infrastructure (GSI) along this stretch of roadway between Drexel Road and Irvington Road. GSI will replace existing painted asphalt sections with trees and landscaping that provide shade and beautification while collecting storm water and conserving water.
English Study Summary(PDF, 2MB)
Spanish Study Summary(PDF, 2MB)