If it's having a hard time both identifying an object, as well as measuring it's movement, there's not really any reason it should understand that all those sep

If it's having a hard time both identifying an object, as well as measuring it's movement, there's not really any reason it should understand that all those separate data points are the same object. That is, it doesn't really matter if the object history is "deleted" or not; if it can't associate a new data point with a previous history (by identification or predicted position), the practical result is the same as if there is no object history. This could be a result of using velocity based tracking, which I don't know that Uber uses, but is a fairly standard method, as it's what raw GPS measurements are based on.