Burning smell, possibly rubber, and smoke from Right Front tire.

A few weeks ago while driving home from work, a lady in a convertible
flagged
me and said my right from tire was smoking and she could smell burning. I
hadn't
noticed it but once my window was down so I could talk to her, I definitely
smelled
it.  Never saw smoke.  

Flash forward a few weeks later, I do smell a burning type smell when using
the
car now. It's not horrible with the windows closed, but is pretty unpleasant.

This morning however, I kept smelling it, and then at a stop light I saw smoke
billowing out as well.  I pulled over and looked.  It was hard to tell where the
smoke was coming from. It seemed to  be just kind of emanating from the
tire,
more so from the side facing the car.  It stopped within a few seconds of
watching
it.  It didn't smoke from what I can tell the rest of the way to work, but I could
smell
it. I kept my speeds down. I have noticed the faster I go, the more it smells,
and
the smoke doesn't seem to start until I'm going fast (60+) for a couple
minutes.

The area definitely does feel a bit warmer than the back tire area after
driving, but
doesn't seem to be more warm than the front driver side tire well.

One thing I did notice, is that the back tires and the driver front all look really
good
with the tire threads, but the front right one is super worn down.

I'm going to have the right front tire replaced, but was just curious if having
the
one worn tire and three good ones could cause a smell and smoke like that,
or if
there is likely something else going on.

Appreciate any assistance.