Interchanges obsolete after only 20 years because of poor planning / malfeasance

[Road Hog]

I-49/I-30 is currently under construction, and it is an underpowered 3/4 cloverleaf with one flyover.  It will need to be replaced soon enough.

The one flyover is curious. My guess is the fourth cloverleaf was left off because of the farmhouse in the northwest quadrant of the interchange. That's how AHTD rolls.

[apjung]

I-12/I-55 cloverleaf interchange should have been a stack. It was probably adequate when the speed limit was 55 but it's a little more tricky to slow down from 70.

[Occidental Tourist]

The rebuilt CA-22 east to I-5/CA 57.  They rebuilt it about 7 years ago and added a collector lane, and the whole thing backs up about 3 miles during rush hour.

The rebuilt CA-57/60 merge.  They built a truck bypass lane on the southbound lanes that trucks don't have to use.  There is very little difference in the pre-rebuild and post-rebuild traffic.

I-15/CA 91 interchange.  It was built 25 years ago.  For the past 15 years on weekends the northbound 15 to westbound 91 lanes regularly back up.