There are some things you can do to maintain the tires on your vehicle and get more life out of them. Checking and correcting wheel alignment on the car is one of those, and there are some specific reasons the alignment can change over time.
Your vehicle's suspension plays a significant role in how the tires contact the road surface and what sections will wear first. If the suspension has worn parts in it, the wheel alignment can wander, and the position of the tires on the road can lean in or out and cause uneven wear along the edges. This condition is referred to as positive or negative camber and should be corrected with wheel alignment.
This will eventually wear the side of the tire tread enough to damage the tire, but a wheel alignment can help detect and correct this issue. The worn suspension parts will need replacing before a tech can set the alignment, but the initial alignment check will show where the problems are and give the technician a good starting point for repairs.
Sometimes regular tire rotations can minimize the wear, but they can also hide the problem, so it is essential to check the alignment when installing new tires and after suspension work has been done to your vehicle.
In the front of your vehicle, worn steering components can cause similar issues as the suspension parts, but often instead of camber problems, the tires wear because of a toe in or out condition. This means the tires are pointing in at each other or out away from each other. In both cases, it will cause the tires to scrub on the pavement and damage the tread badly over time.
Often you will notice the car handling poorly as well, and this should be an indication to have the wheel alignment checked by a tire repair shop that offers alignments. If the toe is off, the technician will need to check the steering parts under the car to determine if there is something bent or damaged, if the tie rod ends are heavily worn, or if the ball joints and suspension parts are allowing movement in places they shouldn't be.
In extreme cases, the handling can become almost unmanageable and the vehicle so hard to drive that it is not safe. While parts wear is often the reason for the changes in the handling, an impact with a pothole, debris in the roadway, or hitting a curb can alter the wheel alignment enough to cause some of the same handling issues.