National Route 4 intersects the Beltway at its southern-most and eastern-most points to go through Koiwai. Along its southern side, it runs concurrent with the Koiwai Bypass. The eastern intersection between the two and National Route 104 is known as the Five Points Interchange. National Route 404 is twelve lanes long for most of its length, with 16 lanes at the Five Points Interchange and eight lanes at the Ulei River Skyway. The four inside lanes are always used as High-occupancy vehicle lanes.