Because in a day, any period of time, actually, no, I shouldn't do a day. We have to assume that every hour is completely just like any other hour. And actually, even within the hour, there's really no differentiation from one second to the other in terms of the probabilities that a car arrives. So that's a little bit of a simplifying assumption that might not truly apply to traffic, but I think we can make that assumption. And then the other assumption we need to make is that if a bunch of cars pass in one hour, that doesn't mean that fewer cars will pass in the next. That in no way does the number of cars that pass in one period affect or correlate or somehow influence the number of cars that pass in the next. That they're really independent.