But Downtown Links isn't a freeway.
The Sonoran Corridor would be a nice connection between the airport, the Port of Tucson (rail), and the freeway system. It makes a lot of sense, and it is well away from the main population areas. But I'm not sure it will ever happen in my lifetime, given this area's history with freeways.
It's a wide urban boulevard being sliced through downtown requiring major eminent domain. And it may not be a freeway now, but I think they could elevate some of the lanes in the future.
Links is certainly a shell of the 210/I-10 connection once envisioned by ADOT, and the design looks like a complete charlie foxtrot as far as traffic signal spacing and sight lines are concerned. In due time the handful of crappy buildings the city has managed to save by shoehorning in the surface street may eventually lose their "historic value" and be torn down to make way for a beefier connection to the interstate. Frankly it's been needed since ever since Tucson put in the trolley and put Congress and Broadway downtown on road diets a while back.
Frankly any hope of a freeway in the city proper north of Golf Links road is probably a lost cause A loop freeway along houghton/ina/skyline would either involve tearing down a bunch of rich people's homes, or routing along the washes. Fat chance of either.
Suburbs, however, are a different story. I'll have to dig up the link but there's plans for 4-5 lanes each direction on I-10 between the eastern 210 link (It's supposed to tie in near the current Craycroft TI) and AZ 83. I can see Sahuarita, Vail, Corona De Tucson and other future growth corridors on the south and east end of the metro being very supportive of freeways as they tend to lean a little more right, politically.