In the public right-of-ways, functional and beautiful streetscaping will complement the landscaping on private property. Streetscaping will be added in and along roadways, sidewalks, and alleys in both neighborhoods. See the preliminary plans for MacFarland and Lafayette.
Documented benefits of streetscaping include traffic calming and pedestrian safety; improved paving surface; and preservation of existing trees. Possible features for the target neighborhoods include:
These vegetated areas project out into the roadway and accept and infiltrate stormwater runoff from the road. Street gardens have the additional benefit of narrowing the roadway, thus acting as a traffic calming measure (similar to speed bumps--but more attractive!), and in making road crossings safer for pedestrians by reducing crossing distances. These are good ideas where roadways are wide and near schools and parks for traffic calming. Street gardens sometimes require the loss of parking spaces so they may not be appropriate in neighborhoods with high on-street parking pressure.
Infiltration Tree Boxes
These vegetated areas between the sidewalk and the street accept and infiltrate stormwater runoff from the road. Unlike street gardens, infiltration tree boxes do not project into the road so they can be used without losing on-street parking spaces. However infiltration tree boxes should only be installed where there is no large tree already present in the tree box because their installation can injure or kill a tree.
Tree Box Planting
Tree box planting is simply installing trees in the space between the sidewalk and the roadway. Although planting trees in these areas does not capture runoff from the roadway, mature trees do intercept and capture rainfall before it reaches the road and becomes runoff.
Porous materials allow rain or snow melt to percolate through and infiltrate into the soil below. There are three main types: pervious concrete, porous asphalt, and pervious pavers. Porous concrete and asphalt look similar to regular roadway materials. Pervious pavers are materials like brick, cobblestone, and concrete pavers that are spaced apart to allow water to infiltrate between them. The renovated Petworth Library features a parking lot with pervious pavers. Different colored pavers are used to designate parking slots. See examples below.
A 12-inch trench full of gravel is the foundation for brick-like pavers. Different colors make an attractive design.