IOT project which count the number of passengers in a Transport bus and one who connected to internet can check is the bus is crowded or not

This is an IOT project which helps the Bus travelers to know the rush in the bus in-order to take proper decision based on it. For example if someone heavy and breakable things in his/her hands then it is not safe to travel in a crowded bus but in-order to know the status of the bus one should wait until the bus reaches the stop. But if you know the number of passengers the bus in the before the bus reach the stop then we could save time and take a taxi.