How do you know if you have enough room to change lanes?

How do you know if you have enough room to change lanes?

I know your supposed to look in the mirrors and in your blindspot, but how do you know if you have enough space between you and a car in the lane you are moving into?How do you know if you have enough room to change lanes?
Don't drive a car until you figure this and a lot of other things out. Maybe like, what is my name? What do the arms on a clock mean? Do I turn on the garbage disposal while my and is in there or after? - You gots some learnin to do boyHow do you know if you have enough room to change lanes?
If you can't see the whole front of the car in the other lane in your rear view mirror, you aren't leaving a safe distance. People cut that short regularly, and it really ticks me off, as it is a symptom of the decreasing respect for the property, and the very lives of others. When I learned to drive, it seem everybody learned the above rule, now it seems only half the people in the world do. Note you can leave less space in very slow traffic, buy anything 30 mph hour and above, you need to do it the way I explained it, and you will NEVER have to worry about cutting anybody off.
try to leave at least two car lengths between yourself and others on the road at all times. In tight situations I'd say you can squeeze in with only maybe one car length but If it were me i would plan ahead and signal a little earlier to make sure the car behind or in front of me knew what I needed to do.
if they are behind you accelerate forward so they dont hit you from the back. if they are in front, slow down until you can get over without hitting the back of them and there is enough space behind and then go.
If you have to ask yourself if you have enough room you probably don't. Take other drivers into consideration. If not, accidents result.