The air-filled or pneumatic tire is composed of a core filled with airtight sealed pressurized air. Usually, a reinforced steel belted tread or other materials, seals this inner core and provides the contact part with the road.
As the pressure of the air in the tire is greater than atmospheric air pressure, the tire remains inflated even with a vehicles' weight resting on it. The pressure of the air in the tire gives resistance against forces which attempt to deform the tire. When the tire hits bumps in the road, this gives the tire a slight degree of a cushioning effect. If you have experienced taking a ride in an old-fashioned carriage that had wooden wheels, you know how big of a difference a set of pneumatic tires can make.
Of course, there are several drawbacks to pneumatic tires. Like for example in high-performance situations or highly dangerous applications, these tires can suffer a puncture and this will result in a total failure. The consequence of a blowout at high speeds can lead to a serious car crash. Military planners should consider tires getting blown out by explosion shrapnel or shooting of guns. The worst nightmare of a vehicle crew is becoming trapped in a fire zone because of all of their tires becoming flat. Airless tires obviously don't suffer from these issues and thus, may be more suitable in certain applications.
The pneumatic tire may have problems as well with the variation in air pressure and tire performance. The lower pressure in a tire may increase the traction and the comfort level. This is due to the fact that tires flatten a little and more tread is placed in contact with the road. The air pressure inside of the tire works to maintain the lateral stiffness of the tire as well as maintain the "up and down" stiffness. Thus, less air pressure allows the tires' sidewalls to flex. Unfortunately, this results in poor handling. In an airless tire, the stiffness in those two dimensions is independent.
Air pressure factors into other issues also. With regards to to maintaining proper air pressure, consumers are notoriously unreliable. Incorrect air pressure inside tires can lead to very unsafe situations. It is really essential to note that pneumatic tires are also prone to temperature changes, that could be responsible for changing the internal pressure of the tire. It is very essential to take into consideration the type of environments you would be needing your equipment to function in so that you could frequently check the tires and keep the equipment as safe as possible.