If you wonder if you have enough distance to the car in front, you can use the three-second rule.

This rule states that you should pass a given point on the road at least 3 seconds after the car in front of you has passed it. Look at the road, mark a point where the car in front of you is, and check how many seconds it takes to reach that point. On slippery roads, or when driving conditions are difficult, the distance should be more than 3 seconds.