When my car was making a loud humming sound while driving it turned out to be the front wheel bearing going out.
The wheel bearing was a complete wheel bearing and hub assembly that had to be replaced all together becuase it was one piece.
As I drove the humming noise started getting worse and worse and louder and eventually it started making a grinding noise.
What I did was jack up the car and spin the wheel by hand and listen to see if I could hear that humming noise or loud grinding noise and I heard the humming noise and when spinning it faster I started hearing the grinding noise.
If it's the wheel bearings you need to replace the bearing assembly soon because it can cause an accident and damage your vehicle as well.
Another cause could be tire noise or road noise but I would check the bearings or have a shop check the bearings because that's the most common culprit of a car making a humming noise when driving.
If your car has over 100,000 miles on it then the bearings are likely the culprit.
Another cause could be a worn transmission or the CV joints being bad but they may also cause a clunking sound when you hit bumps.
If the tires are the cause of the humming noise while driving then it's usually caused by the tires tires chopping or cupping.
The wheels could need aligned because they could be out of alignment.