Concrete – Suggestions for dealing with the sharp corner of a storm drain

The (city-owned) storm drain outside my house has a corner that protrudes about half an inch from the line of the sidewalk. It's sharp enough to puncture a tire; I've lost a few to it over the years, as have my neighbors. Complaining to the city has had no effect.

So I'm thinking of doing something about it myself. My thought is to fill the space out with some concrete. Any suggestions on the exact steps to take so that it'll bond properly and not flake off if a tire hits it while parking?

(The alternative, I suppose, would be to grind down the corner, but that sounds hazardous.)