Some feel the need to begin their work day on the commute. If they are on a train or a bus or not the one driving the carpool, they are on their phones and laptops doing work.
(Hopefully, the driver is not!)
If you get an email or a call from your boss during your commute, you’re going to take care of it. So that’s all work time.
Some studies say YES, you should get paid for that.
There are those that say no, saying they like having their commute to mentally switch from home mode to work mode.