The Parleys Canyon Interchange in Salt Lake City between I-80, I-215, Foothill Drive, and Parleys Way may finally get a redesign, according to UDOT's draft EIS released last month (https://www.parleyseis.com/#resources). Aside from a recent pavement and re-signing project, this interchange is essentially unchanged from when it was built in the mid-1960s and has lots of tight curves, short merges, and even an undivided ramp connecting northbound 215 to eastbound 80 and vice versa (https://goo.gl/maps/MHCwmcqhPnf1APQp9).
According to the alternatives analysis (https://www.parleyseis.com/assets/docs/deis/Parleys_DEIS_02_Alternatives.pdf), the preferred alternative would:
- Widen I-80 to three lanes each direction through the interchange
- Divide the substandard SE ramp and widen it to 2 lanes each direction
- Remove the existing bottleneck on I-215 south where it currently narrows to one lane before the Foothill merge
- Shift the I-80/215 junction east and remove the left merge from 215 to 80 westbound
- Add slip ramps/braided ramps to I-215 to reduce weaving between the 3300 South and I-80 exits
- Eliminate the loop ramp from 80 eastbound to Foothill and relocate it to split from 80 between 23rd East and 215, following the north side of I-80 and merging directly into the Foothill ramp from westbound 80
Quote from: US 89 on March 07, 2020, 01:49:45 PM
The Parleys Canyon Interchange in Salt Lake City between I-80, I-215, Foothill Drive, and Parleys Way may finally get a redesign, according to UDOT's draft EIS released last month (https://www.parleyseis.com/#resources). Aside from a recent pavement and re-signing project, this interchange is essentially unchanged from when it was built in the mid-1960s and has lots of tight curves, short merges, and even an undivided ramp connecting northbound 215 to eastbound 80 and vice versa (https://goo.gl/maps/MHCwmcqhPnf1APQp9).
According to the alternatives analysis (https://www.parleyseis.com/assets/docs/deis/Parleys_DEIS_02_Alternatives.pdf), the preferred alternative would:
- Widen I-80 to three lanes each direction through the interchange
- Divide the substandard SE ramp and widen it to 2 lanes each direction
- Remove the existing bottleneck on I-215 south where it currently narrows to one lane before the Foothill merge
- Shift the I-80/215 junction east and remove the left merge from 215 to 80 westbound
- Add slip ramps/braided ramps to I-215 to reduce weaving between the 3300 South and I-80 exits
- Eliminate the loop ramp from 80 eastbound to Foothill and relocate it to split from 80 between 23rd East and 215, following the north side of I-80 and merging directly into the Foothill ramp from westbound 80
Lowkey miss the old alternatives with the conversion to a stack but again the terrain for the interchange is absolutely fucked so sticking to Alt B won't hurt. I kind of like Alt A better but they're the ones running the simulations.
However, I would say, if this doesn't include some study of widening Foothill to 6 lanes from 23rd to the interchange this is still gonna be a shit show every rush hour. And on further pipedream levels of imagination, if there were any stretch of highway in the Salt Lake Valley that could use commuter/express lanes a la SR 92, it would be Foothill up to at least Sunnyside or the U of U entrances, so I'd look into that somehow too.