It took my friend and I about an hour and a half to two hours to do the scenic 15 mile drive. We stopped multiple times along the way to hop on some rocks and take pictures.
This place is beautiful whether you want to hike it or just see it from the comforts of your car. The staff at the visitor center were really friendly and so was the park entrance staff. We ended up staying almost 40 minutes at the visitor center because it had a lot of neat souvenirs and educational dialogues throughout.
Make sure you either bring some water or stop by the visitor center before you start the drive! It's a one way road!
Loved the place. Will do it again in a couple of years and hike if.