Some people, like me, cannot begin the day without coffee.
If your day basically starts with your commute to work, then taking your coffee with you in the car is a likely option, particularly if you have a coffee mug designed for this purpose. Coffee mugs which are used in cars are often shaped to be more stable, with a wider bottom, or they are designed to fit neatly into the drink tray of a car.
Take-out coffee cups are also designed to fit into your car's drink tray, and, hopefully, the cup comes with an insulting extra layer, so you don't risk burning yourself.
Additionally, you should have a lid properly placed on any coffee cup which will ride with you in your car, since a sudden move could force the liquid to overflow.
Most people prefer to drink their coffee hot, or at least warm, so if your commute is rather long, you might choose to take your coffee in an insulated mug or thermos, which will not let your coffee get cold. Many insulated mugs are built to be very sturdy, and have special mouth pieces, just in case they are dropped. These are often called tumblers precisely for that reason. The good news is that if you drop a coffee tumbler, and you have closed the lid correctly, you will not spill hot coffee on yourself or on your car seat. And probably save yourself thousands in insurance and hospital bills
Insulated travel mugs and thermoses can also be used to keep drinks cold. On scalding days, when you're stuck in a traffic jam, it is a real relief to take sip of a cold drink. Also, the temperature inside a vehicle can rise to be dangerously high if the car is parked in the sunshine. A thermos or insulated mug will keep your water or cool drink at a refreshing temperature.
One of the advantages of a well designed travel mug, is that they are often lined with a non-slip surface, so that the cup does not slip out of your hand or out of the cup holder. Some particularly well designed liquid containers are very stable, with a weighted bottom, and some other features like ergonomic handles and mouth pieces. While you are driving, always use only a coffee mug or cup which is appropriate for this purpose. This way, you will protect yourself and your vehicle, and avoid accidents.