Asked by: Tom Obermeier, via email
Listening to a podcast is usually a passive enough activity that it leaves ample mental resources for you to do other things at the same time, including driving. This contrasts with when you’re performing two tasks that are both mentally demanding – having a conversation while driving, for instance. In this case, both tasks require all (or nearly all) of your mental resources, so you are switching back and forth between the two, and probably doing both badly.
Many studies have shown that, whereas conducting a phone conversation (even hands-free) has a detrimental effect on drivers’ performance, listening to the radio does not. And when the driving does get more demanding – perhaps the traffic gets heavy – a University of Groningen study showed that drivers naturally disengage from or block out the radio or podcast to focus more on driving.