How to Build a Compact Japanese Interchange in Cities Skylines

How to Build a Compact Japanese Interchange in Cities Skylines

Japanese expressway interchanges are engineering puzzles squeezed into impossibly tight spaces. Episode 7 builds the Takeishi Interchange — an open-cut junction where E1 meets the underground E2.

What Is an Open Cut Interchange?

A below-grade trench instead of elevated ramps. Buildings can be constructed right up to the retaining walls — which is exactly what happens in Japanese cities.

Trench Construction and Ramp Geometry

We lower the terrain and place retaining wall assets. Node Controller adjusts curve radii, Network Multitool sets slope gradients. Japanese expressway ramps max out at 5-6 percent grade.

Road Marking — The Critical Detail

Using IMT: edge lines, lane dividers, chevron markings, speed advisories, and arrow indicators. The most time-consuming but most impactful part of the build.

Why Compact Interchanges Matter

Default interchange templates are oversized by Japanese standards. The compact approach reclaims space, reflecting how Japanese expressways are woven into the urban fabric rather than carved through it.

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