Ultimate 4-way intersection
Ultimate 4-way intersection has no weaving, merging and junctions at all. So, no! it’s not a roundabout.
It’s compact with size 40×40. It’s cheap and terrain friendly since it’s very simple with most roads on ground and doesn’t have a lot of elevated/underground roads. It works best with completely free flow when you use lane connector from TMPE (exact connections shown on images) and when you have space before and after intersection to avoid lane change madness (You can use 4+ lane highways to help with that). U turn is technically possible, but enabling it by not using TMPE lane connectors properly, would involve a lot of weaving and CSL traffic doesn’t really need U turns.
