NASCAR Racing: 43 cars?, pit lane, nascar

Question
Simple question .. why are there 43 cars allowed to race? why not 40.. 39? whatever.. how did they decide on 43

Answer
This is a tough question.
Because I am not a NASCAR official I am not certain, but...

43 is the number that NASCAR felt was a good number. This number so far has kept competition close and exiting.

If NASCAR let all the 50 or so drivers race that want to(this would include the "go or go home" drivers) The field would be huge, Pit lane would be tragedy waiting to happen, and there would be so much lapped traffic it would be nearly imposible to pass the leader at any track.

hope I answered you question