City of Angels! City of Stars!

City of gridlocked freeway interchanges!

Getting trapped on Los Angeles' majestic, but traffic-jammed freeways, is such a routine local experience that filmmakers turned it into a rousing musical number, "Another Day of Sun," for the Oscar-winning movie La La Land. (I lived in LA for a decade and immediately recognized the gigantic 105-to-110 interchange, which provides an inspiring view of downtown LA for travelers coming in from LAX. Interestingly, I never got stuck in traffic there.)

The University of Southern California's Annenberg School of Journalism and Viterbi School of Engineering's Integrated Media Systems Center have joined forces to crunch the numbers on LA's most affectionate regarded and widely despised local "problem" — traffic! The results are titled "Crosstown Traffic."

A common experience when negotiating the city's biggest and busiest freeways is cruising along at a decent velocity and then slamming into a backup, where freeway meets freeway and motorist switch from driving, say, west to turning north.

This roils traffic on the adjacent surface streets, where drivers jump on and off the freeways.

Here are the worst freeway interchanges in La La Land, as assessed by USC's Jenny Lower in "When Freeways Cross, Everything Gets Tangled":