[dredmorbius]

Dialing 911 (in the US) is still an avenue to getting that help.

[rayiner]

Calling 9/11 on a person with mental issues is liable to get them shot.

[dredmorbius]

There is that possibility, though some areas will have an emergency medical / mental health response.

That said, do you have a better suggestion?

[amyjess]

If they were a clear and present danger to themselves or others, sure. Yelling at cars on the street doesn't hit that level, though.