March 25, 2010: It turns out I’ve only photographed this exit once because watching for merging traffic takes priority.
There are fewer pure cloverleaf interchanges in Iowa than you might think, but two of them – I-80/I-380 and I-35/US 30 – have one big thing in common: The most important traffic movement is an inner loop. In this case, it’s northbound I-35 to westbound 30, traffic from Des Moines going to Iowa State University.
A meeting next week and a KCCI story (warning: autoplay) show that the DOT is out to change that (PDF), creating a flyover ramp to replace the loop. The result would be a “flipped image” of the current I-380/US 20/US 218 interchange in Waterloo. All exiting traffic on northbound 35 would take a ramp and then that ramp would split into eastbound and westbound 30. This plan puts some additional pressure on closing the intersection on 30 to the east of the interchange, where I noticed a long backup of traffic wanting to turn left in my most recent visit to Ames.
As for 80/380, that’s going to be replaced as well. Both of these ramps could be in their new configuration by the end of the decade.