Boston Complete Streets: Design Guidelines
The Boston Transportation Department and other Boston city agencies have developed Complete Streets guidelines that incorporate green infrastructure components such as permeable pavements and street trees to address impacts of climate change including increased heat and precipitation. “Complete streets” are designed to create more sustainable transportation networks by encouraging multi-modal travel options and enhancing the natural environment within the public right-of-way. By promoting the use of green infrastructure, the City can help reduce the urban heat island effect and mitigate flooding. The City is also designing and constructing projects in different neighborhoods that utilize the Complete Streets approach and green infrastructure features. Boston’s streetscapes provide significant opportunities for the City to help reduce and manage flooding and pollution from stormwater runoff, as streets and roads represent over half of the City-owned property in Boston.
The Boston Complete Streets guidelines contain design specifications for different components of the street system including sidewalks, roadways, intersections, and curbsides. The guidelines for streets and sidewalks in particular promote a series of green infrastructure measures to manage stormwater and reduce flooding and soil erosion, and to provide a cooling effect. Sidewalk design specifications aim to divert stormwater to soil instead of pipes, limiting the inundation of water in storm drains. Rain gardens, stormwater planters, and permeable paving on sidewalks also prevent runoff onto roadways.
One green infrastructure component, permeable paving, helps reduce overall stormwater runoff volume and prevent pollution of watersheds, by filtering precipitation and runoff through the paved material so that it can be absorbed into the soil underground or help recharge groundwater. The guidelines recommend using permeable paving for sidewalks and a variety of transportation infrastructure including parking areas, alleys, and pedestrian areas along streets.
Vegetative structures along streets also prevent erosion and degradation of the pavement and sidewalk, and help improve water quality by filtering runoff. Stormwater planters and rain gardens both contain highly porous soil that collects runoff and diverts it back into the ground. Street trees capture stormwater and reduce the volume and temperature of runoff by capturing rainfall that is filtered through the soil. Rain gardens can also provide a space for snow storage during the winter. Trees and other greenery along streets also reduce the urban heat effect Boston often experiences by providing shade and through natural plant transpiration and evaporation processes. While vegetation cools the air around busy streets, the greenery also helps reduce greenhouse gas emissions by capturing carbon in the atmosphere.
The Boston Complete Streets guidelines are intended to guide neighborhood redevelopments and new construction, and projects are already underway that incorporate green infrastructure methods for managing the impacts of climate change. For example, construction on the Peabody Square project in Dorchester, MA was completed by MassDOT in September 2012, and included the installation of pervious sidewalks and rain gardens for stormwater management. It was designed by the City of Boston, supported by ARRA funds.
Boston Complete Streets began in 2009 under then-Mayor Menino as an effort to develop new guidelines for street design to reduce flooding by managing stormwater, and build safer roads shared by cyclists, pedestrians, public transit, and cars. Complete Streets is a nationwide movement that brings sustainable street design to cities around the country in an effort to create safer, environmentally friendly streets for all modes of transportation. Complete Streets was launched in 2004 by the National Complete Streets Coalition, a program of Smart Growth America that brings together public interest organizations and transportation professionals.
City projects utilizing the Boston Complete Streets guidelines are managed by different city departments including the Public Works Department, Boston Transportation Department, and the Boston Water and Sewer Commission. Trees and sidewalk vegetative plantings are managed by the Parks Department with Public Works, as are stormwater management elements (with help from the Water and Sewer Commission). City-initiated projects are funded by through the City’s annual Capital Plan, and state and federally funded projects are usually funded through the Transportation Improvement Plan of the Boston Metropolitan Planning Organization.
This Adaptation Clearinghouse entry was prepared with support from the Federal Highway Administration. This entry was last updated on January 28, 2016.
Publication Date: 2013
- City of Boston, Massachusetts
- Boston Transportation Department
- Best practice