Existing Conditions
Urban boulevards have historically been designed to maximize automobile throughput, often resulting in poor conditions for people walking, biking, and riding transit. Like other wide arterials, they are prone to frequent speeding and unsafe vehicle operations, but are vital routes for all modes.
Land use and destinations are often mixed and dynamic, with many different types of users and visitors. Both through movement and destination access are in high demand.
Boulevards include broad swaths of impermeable surface that exacerbate stormwater runoff and outfall events. A wide right-of-way with multiple roadbeds creates a complex context for managing a significant volume of stormwater runoff. During heavy rainfall, the service roads—where most walking and bicycling activity takes place—are at particular risk for fast-moving runoff streams and pools.
Recommendations
Boulevards provide some of the greatest opportunities for green stormwater infrastructure in cities, due to their large impermeable footprints and extraneous motor vehicle areas. Service road medians and curbsides provide significant space for water retention, storage, and treatment.
Mature trees—which perform significant stormwater management—and historic or unique urban design can be found on many boulevards, and should be used to anchor public space and placemaking opportunities. Integrate water management into the aesthetic of the street to create high-quality, comfortable places for people, while designing to protect and promote the root structures of mature trees.
This left turn lane has been shortened and signalized, and the median has been extended as a refuge. Boulevards require careful design at intersections with cross traffic. Enable pedestrians to make safe, easy crossings at desire lines at each intersection, and at least every 300 – 400 feet on long blocks. Manage or restrict turns from the center roadbed to eliminate unsafe turning conflicts.
Transit stops and stations, especially on the side median, are ideal siting opportunities for bioretention facilities, and may be continued as linear pedestrian spaces to improve pedestrian access and comfort.
Though center median facilities provide large linear footprints, they may be more expensive places to implement bioretention facilities, as they are often difficult to access for maintenance and may require reversal of the roadway cross slope to redirect stormwater runoff to the median. Assess costs of siting bioretention facilities in the median in context with potential benefits, and consider whether street trees are better suited to that space, which still improve shade canopy and perform some infiltration.