I agree speeding is a problem here. This street, as well as all other residential side streets throughout New Haven, should be posted at 15 or 20 miles per hour.

Within residential sections of other Connecticut towns and cities, posted speeds of 15 or 20, and sometimes even 10, are common. Speeds of more than 15 or 20 are unacceptable in residential areas because they create noise and lead to numerous pedestrian injuries, and sometimes fatalities of young children. Are New Haven's children worth less than the children of other towns and cities in the state?

In the medium-term, narrowing the street down by deploying changes to the physical condition and/or the visual perception of it, including adding trees as you suggest, would be even more effective.

There are dozens of options for doing this, ranging from more costly to less costly:
-New curbs, bump outs, chicanes, physically narrow streets
-Raised crosswalks at intersections, like the one shown here
-Alternative Painting and striping techniques, additional speed limit indications
-Many types of so-called "temporary" (in reality, semi-permanent) traffic calming measures that the city has largely ignored up to this date, even though they cost almost nothing to install and are extremely effective.

In order to get this going, have you considered working with your local Aldermen & neighbors to submit a "Complete Streets Request Form"? They are available at http://www.cityofnewhaven.com/Engineering/completestreets.asp. I believe that getting these types of public requests on the official record, alongside similar requests from the many other neighborhoods within New Haven, will help provide an impetus for the city improve the safety of roadways over time. The requests will be documented in annual reports and implementation (or lack of) can be tracked each year.

If you need help completing the form itself you may want to contact your local alderperson, some of the folks at New Haven Safe Streets at newhavensafestreets at gmail.com or folks at Elm City Cycling, a bike/pedestrian advocacy group at elmcitycycling.org.

Good luck!