Hexchange
Decided to create another city center highway exchange since I wanted to increase inbound/outbound highway traffic on my city map.
Works really well so far in a city of 30k and all high density zoning. Tested with my “bowtie access” highway intersections and the combination can push a lot of traffic with surprisingly little congestion.
Naturally being this large it requires a large, flat area and a ton of cash.
All roads should be upgradable, though the normal city streets that go under the highway may be tricky to upgrade to 4 and 6 lane avenues.