Agree this is an issue, one that has been well documented by the community for many years. See request item #3 in this 2011 letter, signed by 100 residents and area elected officials, for instance: http://www.newhavensafestreets.org/2011/09/coalition-receives-response-from-mayor.html

Nothing meaningful has been done by the city.

Enforcement would have little long-term impact - the road needs to be "self-enforcing," that is, designed in a way that causes drivers to travel at the speed desired by the community.

Many US cities, and thousands of cities in other countries, are now implementing 15 to 20 mile per hour limits throughout areas like this. They are enforcing them through good design. Edwards & Livingston is an example of a self-enforced in New Haven, though similar measures can be implemented for a lot less money.

I suggest contacting your Alders and the City directly and collecting petition signatures of at least 100 residents. Following the letter I referenced above, the Mayor and City Staff repeatedly said that they would be doing something about this -- including studying the conversion of Elm, Edgewood, Chapel and George in the Dwight/West River/Edgewood area back into slower, two way streets -- but I haven't heard of any follow up.