I'm pretty sure it would be easy to predict the spikes in usage. In the mornings people mostly want cars near their homes to take them to work. In the afternoon/evening they want cars near work to take them home.
Even without knowing this it's pretty obvious that if you have a large portion of users heading to one area (increasing the density of users in that area) they'll probably want to leave that area or move around it so you should have a higher density of cars in that area even if they aren't all being used.
Even without knowing this it's pretty obvious that if you have a large portion of users heading to one area (increasing the density of users in that area) they'll probably want to leave that area or move around it so you should have a higher density of cars in that area even if they aren't all being used.