Driving on bald tires can be treacherous in the best of conditions. Add some rain or even worse snow or ice, and the results could be tragic. We’ll show you how to determine if your tires need to be replaced.

One way to know you have enough tread is to insert a penny upside down into the groove and see if you can see the top of Honest Abe’s head. If you can’t, you have enough tread. If you can, then it’s time to replace the tire.

Another is to look for tread wear indicators, which are ribs, inside the grooves that run across the tire’s surface. If the tread has worn down to that level then you know it’s time for a replacement. But bear in mind, the deeper the grooves, the better the tire is going to be in snow and on rainy roads.

Also be on the lookout for uneven wear. For example, if there’s more wear on one side of the tire than the other, it can mean there’s a misalignment or a broken suspension component.

If your tire shows cupping, which is dishing out high and low spots, your shock absorbers are dead and your tire has literally been bouncing down the road.

Finally, take any sidewall damage very seriously as it can lead to a blowout, which can be extremely dangerous. Sidewall damage cannot be repaired.