i saw a woman putting air into an obviously soft rear tyre. she'd got no idea what to do, it was a meter that you pre-set digitally. she thought air should come out before you put it on the valve ! she couldn't hear any air going in so kept pressing the increase in pressure, when i eventually lost patience waiting to do mine i went to help her and found that the tyre she was working on had 93 lbs in ! i corrected this,and when i checked the offside tyre there was 19 in, but she said it looked alright thanked me and drove off. it really frightens me to think what's coming towards you on the road these days more than years ago .so little knowledge.