A better south-side connection This summer Tucsonans saw the years-long Interstate 19 and Ajo Way interchange completed. The improvements include widening Ajo Way and the southbound lanes on I-19 and adding an auxiliary lane for northbound traffic from Irvington Road to Ajo. Two new bridges at Michigan Street and the Santa Cruz River went up in the area. Crews also installed sound walls to protect adjacent neighborhoods from the busy roadway. Crews had been working on the projectâs Phase 2 since July 2018. Protection from the dust The Arizona Department of Transportation is already helping guide drivers through a dangerous section of Interstate 10 prone to dust storms in 2020.