Thank you, the smooth animation was only possible thanks to the DeckGL framework. In the past I tried using only MapBox, which resulted in laggy animations. I do enjoy seeing the city "pulsing" with the day/night cycle.
I think a good solution for this problem would be to discard all routes where cars take more than twice the expected time. This would result in loosing some legitimate trips (could be stuck in traffic), but by adjusting the threshold this could be alleviated.