to get to Mauna Kea, one has to go thru the Saddle Road.
Wikipedia extract: Saddle road is considered one of the most dangerous paved roads in the state, with many one-lane bridges and areas of marginally maintained pavement. It reaches a maximum height of 6,632 feet (2,021 metres) and is subject to fog and low visibility. Many rental car companies explicitly prohibit use of their cars on Saddle Road. Nevertheless, it provides the shortest route from Hilo to Kailua-Kona and the only access to the slopes of Mauna Loa and the observatories atop Mauna Kea.
Indeed there were lots of bumps, dips and also, we were driving with the top down so it was cold too! We had to buckle up at the back just in case we were flung off during the drive.
as we neared Mauna Kea