I found myself at a rest stop off I-40 drinking terrible gas station coffee when I saw a huge tour bus parked outside, and realized after talking to the driver, who was smoking next to it, that I had seen this bus before. No big deal—until I saw a strange little tube protruding from the wheel. Thought it might be an antitheft thing. It wasn’t. That small cable was part of a Central Tire Inflation System.
I suppose I’d never paid much attention to tire pressure beyond the odd dashboard light. But then I started digging. It turns out this system has been keeping big military trucks, off-road rigs and buses rolling smoothly like a ninja for years.
A Central Tire Inflation System (CTIS) allows drivers to check and adjust tire pressure on the fly. The system is attached to each tire with a swiveling fitting — those mousseline cables you sometimes see dangling from truck wheels. It has an onboard air compressor that can inflate or deflate tires as required.
CTIS helps to regulate pressure according to varying terrain, loads or temperature. No stops, no foot pumps, no guesswork.