The riverbed of the Kanzaki River, which branches off from the Yodogawa River, has
paved road surfaces that continue on and on, but

↑That's roughly where it ends,
and it turns into a rotary-style intersection.
If you turn right up from the riverbed just before this point,
you can ride along the Inagawa River road with almost no traffic lights.

Back in the day, I once did this pointlessly dangerous thing
where three of us would go round and round that last rotary section,
gradually picking up speed.
Even at the absolute fastest, I don't think we hit more than 30 km/h,
but despite being the one who brought up the idea, I chickened out first
and veered off onto the road.
If we'd kept going any longer than that,
we'd have either crashed or turned into butter.