The New Rules for Business Rides in an Uber, a Driverless Car and MoreThere's a proper time to sing, to sleep and to make small talk.

With self-driving cars starting to rule the roads, it's important to know what you can and can't do as a passenger. Here are some guidelines.

When driving the company car, is it tacky to belt out my best Katy Perry impression?
Jeanette Martin, management professor emeritus at the University of Mississippi and author ofThe Essential Guide to Business Etiquette: "Depends on how passionately you're singing! Remember that you're representing the company, so you need to be on your best behavior: no road rage, no giving people the finger, no texting or eating an elaborate lunch at the wheel. Most companies will also give you guidelines on whether you can use the car for personal errands or lend it to a family member. But if they don't, ask. You don't want to find out after your teen gets a ticket that she shouldn't have been driving."