UDOT has been throwing around the idea of upgrading SR-73 to a freeway for a while now. I figured it deserved a separate thread, since it seems to be a totally different project from the Mountain View Corridor (though the projects will tie-in to one another).
Anyway, UDOT just completed a Draft State Environmental Study (https://www.udot.utah.gov/sr73/wp-content/uploads/2018/07/SR73_Draft_SES_07182018.pdf) on this upgrade (warning: it's a 436 page PDF with ugly font :pan:), and an Alignment Map (http://hdr.maps.arcgis.com/apps/webappviewer/index.html?id=10f61e081c2145fcbe4e4e39812d751d) has been published as well.
From what I can see, the plan is to build a freeway with Texas-style frontage roads from the future MVC junction west to Canyon Wash Drive. The road will be widened to four lanes west to Eagle Mountain Blvd, with traffic lights likely installed at Eagle Mountain Blvd and 6-Mile Cutoff Rd. Enough ROW will be preserved for a future interchange at 6-Mile Cutoff Rd (similar to the current MVC sections).
There will be slip ramps for an interchange at Ranches Parkway, as well as WB exits/EB entrances for Mt Airey Drive and Valley Drive (in addition to the ramps where the freeway portion starts and ends).
(https://www.udot.utah.gov/sr73/wp-content/uploads/2017/08/SR-73.RoadwayLanesDepressedElevated-01.jpg)
Project website (https://www.udot.utah.gov/sr73/)
Why is the western part of the proposed freeway elevated?
Quote from: SES, page 15The roadway design is generally depressed (below the existing ground level). Elevated sections are used only to avoid certain utility corridors and existing washes.
There is a significant wash that crosses SR-73 just east of Canyon Wash Road (hence the name). Here's a GSV (https://goo.gl/maps/oAmiWfQ7KMC2).