Inflatable Tank Track

The inflatable/pneumatic tyre was a genuine inflection point in human technological development. Before this, people juddered around on iron-rimmed wooden wagon wheels. Take a look at a a horse-drawn carriage from the past <link>. It's design is dominated by attempts to improve the ride. The wheels are huge, so they have longer contact patches that don't sink as far into small dips. The axles are on elliptical leaf springs and then the passenger compartment is entirely suspended on enormous springs. The lack of a flexible member between wheel and road meant that wheels had to be made resistant to shocks, although they broke frequently anyway. One ride on a bicycle with solid tires* is enough to convince anyone of the value of pneumatic tires.

Tank tracks were initially developed for... well, tanks. Moving at walking pace across soft ground doesn't need much in the way of comfort, and comfort was very much a low priority in the early vehicles. Modern tanks are so massive (60+ tonnes) that they crush a smooth path on uneven ground, yet they often feature sophisticated suspension systems.

So, the idea is to take a standard rubber vehicle track and include a chamber running around the center circumference. This is then inflated with low pressure air, tracks have much more surface area than tires, so this will be between 1/2 and 1/1000th of normal tire pressure, 0.1-15 PSI or so. The track structure will be optimized so that the outer central region bulges out slightly when the chamber is inflated. Now the tracked vehicle rides on the center section of the track suspended on a pneumatic chamber. This pneumatic chamber will conform easily to small deviations offering comfort, extra grip and some additional protection to the track running gear.

It's difficult to place a valve for inflation in this arrangement, however, the pressures are so low, that you could get away with a needle-through a bung type arrangement found on footballs/syringe injection ports.

*Or any car with oversized wheels and super low profile tires, added points if the tires are run-flats with minimal flexibility. As further evidence toward my overarching theory that racing ruins everything, see huge alloy wheels w/low profile tires. Why would you need low profile tires? Because you have huge wheels and the overall wheel/tire still needs to fit. Why do you need the wheels to be made of shatter-prone alloy? Because the weight needs to be kept down on such huge wheels. Why are the wheels so huge? To fit over the massive brakes. Why are the brakes so big? Because that's necessary to cool them. Why so much cooling, because you're losing 100mph 4x in 5 mins, why? Because racing. So the ride in your Audi A5 is jiggly & awful because of the racing you don't do, and a modest pothole will destroy both wheel and tire. Compare and contrast steel-wheeled Ford Crown Vics with normal sidewalls that were specced to be OK hitting kerbs at 40mph.