This central server can then be queried to provide information such as least delay routes or traffic hotspots. On the other hand, Nericell utilizes individuals’ mobile phones to not only determine average speed or traffic delays, but also detect honking levels (especially in countries like India where honking is common) and potholes on roads. Another example is ParkNet [6], an application that detects available parking spots in cities using ultrasonic sensing devices installed on cars
combined with smart phones.