An air-filled or pneumatic tire consists of an inner core which is sealed airtight and filled with pressurized air. Normally, a reinforced steel belted tread or other materials, seals this inner core and provides the contact area with the road.
The tire would remain inflated with all the weight of the vehicle resting on it, because the pressure of the air within the tire is more than atmospheric air pressure. The air pressure in the tire gives resistance against forces which try 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 ever taken a ride in an old-fashioned carriage that had wooden wheels, you understand how huge of a difference a set of pneumatic tires makes.
Of course, there are several disadvantages to pneumatic tires. For instance in high-performance situations or highly dangerous applications, these tires could 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 accident. Military planners need to take into consideration tires getting blown out by shooting of guns or explosion shrapnel. A vehicle crew's worst nightmare is becoming trapped in a fire zone because of all of their tires becoming flat. Airless tires obviously don't suffer from these type of problems and thus, in certain applications, might be more suitable.
Pneumatic tires have one more issue involving variations in air pressure and tire performance. Lower tire pressure can create increased comfort and improved traction. This is due to the fact that tires flatten a little and more tread is touching the road. The pressure of the air inside of the tire works to maintain the lateral stiffness of the tire as well as maintain the "up and down" stiffness. Thus, reduced air pressure allows the sidewalls of the tires to flex. Unfortunately, this leads to poor handling. Within 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, consumers are notoriously unreliable. Incorrect air pressure inside tires can result in really unsafe situations. It is vital to bear in mind that pneumatic tires are prone to temperature changes too, which could be responsible for changing the internal pressure of the tire. It is important to consider the type of settings you will be needing your machinery to operate in so that you can regularly inspect the tires and keep the machine as safe as possible.