A lot of people have pointed out negative issues with calling the police, but there's another factor you're ignoring here, Jack. There's a lot of behavior that falls short of "sexual assault or solicit[ing] prostitution"--behavior that is not illegal, but is <em>absolutely</em> unacceptable in civilized society. To pick a non-sexual example, using the "N" word would hardly be the basis for any sort of police involvement, but it's far beyond the bounds of acceptable behavior for many (I hope most) of us.
If a woman is left with no recourse but to call the police, then any behavior that falls short of illegal is tacitly accepted. But I don't accept it! If you can suggest something <em>besides</em> a code of conduct that would cover behavior in the range between acceptable and outright illegal, I'm all ears, but until then, I'm all in favor of Val's suggestion or something like it.