A pneumatic or air-filled tire is composed on an inner core which is filled with pressurized air and sealed airtight. Normally, a reinforced steel belted tread or other type of materials, seals this inner core and provides the contact area with the road.
Because the pressure of the air within the tire is more than atmospheric air pressure, the tire remains inflated even with a vehicles' weight resting on it. The air pressure within the tire gives resistance against forces that try to deform the tire. This gives the tire a slight degree of a cushioning effect as the tire hits bumps in the road. If you have experienced taking a ride in an old-fashioned carriage which had wooden wheels, you understand exactly how huge of a difference a set of pneumatic tires can make.
Of course, there are some disadvantages to pneumatic tires. Like for instance in high-performance situations or highly dangerous applications, these tires could suffer a puncture and this would lead to a total failure. The consequence of a blowout at high speeds can lead to a dangerous car crash. Military planners should consider tires getting blown out by gunfire or explosion shrapnel. The worst nightmare of a vehicle crew is becoming trapped in a fire zone due to all of their tires becoming flat. Airless tires evidently don't suffer from these type of problems and thus, in some applications, could be more suitable.
The pneumatic tire might have problems as well with the variation in tire performance and air pressure. The lower pressure in a tire can increase the traction and the comfort level. This is because of the fact that tires flatten slightly and more tread is placed in contact with the road. The pressure of the air in the tire works to maintain the "up and down" stiffness as well as maintain the lateral stiffness of the tire. Hence, reduced air pressure allows the tires' sidewalls to flex. Unfortunately, this leads to poor handling. In an airless tire, the stiffness in those two dimensions is independent.
Air pressure factors into other problems also. When it comes to maintaining proper air pressure, customers are notoriously unreliable. Incorrect air pressure within tires can lead to very dangerous situations. It is very vital to bear in mind that pneumatic tires are also prone to temperature changes, that could be responsible for changing the internal pressure of the tire. It is really important to consider the type of environments you will be requiring your machine to operate in so that you can frequently inspect the tires and keep the machine as safe as possible.