Ask HN: Keeping busy during a commute

I've started a new project that will have me commuting 60km a day. The distance is not too bad, but with traffic as it is I'm in the car for a solid hour.

There are a few podcasts I enjoy, but they are relatively infrequent. I'd also like something a little more engaging.

- anyone have experience with audiobooks? Do you need to speed them up? - any other ideas would be most welcome