The Dutch approach is that cycle-priority roundabouts are generally only used in urban areas – note the tight single-lane geometry keeping traffic speeds down (can also put the cycle crossings on raised platforms as well).

Dutch rural roundabouts are typically still motorist priority, although better solutions are usually provided for a busy site like Johns Rd. Given that Johns Rd is a State Highway designed for arterial traffic movement, I think you’d have a hard time convincing NZTA to allow cycle priority anyway. And it wouldn’t be safe to do it across two approaching lanes of traffic – you’re relying on both to stop and not obscure the cyclist (same reason we don’t do zebra crossings on multi-lane roads).

I like the design, but still wouldn’t trust a car driver to look, see and stop.