With older type tires that had a decent sized sidewall you could easily detect when a tire was deflating. It is not so easy with low profile tires. A few years ago I had a new tire deflate on the interstate and it was destroyed before I realized what was happening and brought it to a safe standstill. A can of inflater would have been useless.
85 GTV6 3L
76 Suzuki GT500
2011 Jaguar XKR
A little government and a little luck are necessary in life, but only a fool trusts either of them. - P.J. O'Rourke