Highways and elevated train and subway lines that cut through cities have long been seen as barriers. But through innovative landscape design, the spaces beneath these transportation systems are becoming new linear parks that help bring communities back together. Offering built-in shelter for rain and snow and shade during warmer months, these spaces provide communities and landscape architects an opportunity to create new forms of public space.
After more than six years of planning, design, and construction, the first half-mile-long segment of The Underline, Miami’s 10-mile-long linear park, has opened below the city’s Metrorail system. Designed by a multidisciplinary team led by James Corner Field Operations (JCFO), a landscape architecture and urban design firm, The Underline is a model for how to separate pedestrian and bicycle networks and incorporate exercise facilities and outdoor spaces — all below existing infrastructure.
When The Friends of the Underline, a non-profit organization, and JCFO complete the project, the new park will span from the Miami River in Brickell to the Dadeland South Metrorail station and create more than 120 acres of multi-use public space. Restored natural habitats will mix with public spaces of all kinds along with pedestrian and bicycle paths that link directly to the Metrorail’s stations.
The first segment is already a far cry from what was once there. Isabel Castilla, ASLA, design principal-in-charge for The Underline at JCFO, said: “I still remember one of our first site visits when we had to strategically run between oncoming traffic to cross the street because there was no safe way to cross the SW 7th or SW 8th Street intersections!”
Through outreach sessions, Castilla’s team discovered that improving pedestrian and bicycle access below the Metrorail lines was a priority for the community. “We learned there was a strong desire to create separate paths as some cyclists wanted to travel fast while using The Underline for commuting while others desired a space for strolling,” she said.
To reduce conflicts between pedestrians and bicyclists, JCFO implemented a few smart strategies: “First and foremost, we added traffic lights, pedestrian signals, and crosswalks. Second, the path geometry is always straight and perpendicular to intersection crossings in order to ensure cyclists have proper visibility. All intersections feature designated crosswalks for pedestrians and cyclists in order to give room to everyone and minimize conflicts. Lastly, we implemented bold pavement graphics — not only at intersections to make drivers aware of those crossing on bike or by foot, but also along the bike path to alert cyclists of an upcoming intersection so they can reduce speeds.”
For Alejandro Vazquez, ASLA, design project manager for The Underline at JCFO, the project’s transportation safety benefits are personal. “My grandparents lived in Little Havana and their street didn’t even have a sidewalk to walk on. I remember my grandfather being one of the few people riding a bike in Miami in the 80’s and 90’s, and we were always worried that he would get hit by a car. In a county that has the highest number of pedestrian and bicycle crashes in the state of Florida, the simple act of creating connections through Miami with The Underline’s safe bike trail and pedestrian paths is quite revolutionary. The Underline and its connections to the Metrorail, Metromover, bus transport system, and projected trails—including the future Ludlam trail and the Miami Riverwalk extension—will contribute to a robust network of sustainable mobility corridors.”
The Underline has become part of the greater East Coast Greenway, which runs 2,900 miles from Maine to Florida. Phase one of The Underline links with the Miami River Greenway, and the completed linear park will connect to six major trails in Miami-Dade county.
Beyond the street-level transportation network, JCFO also incorporated a range of public spaces. Brickell Backyard, the first phase of The Underline, found at the northernmost portion, is organized into a “procession of rooms” — the River Room, Gym, Promenade, and Oolite Room. Many of these spaces will also eventually be populated by public art, selected in collaboration with Miami-Dade County Art in Public Places.
The River Room offers views of the Miami River, native and South Florida-friendly plants, and space for residents and their pets.
The Gym is designed for fitness, with a flexible court for basketball and soccer surrounded by exercise spaces that have strength training equipment, stretch and balance areas, and a running track.
The Promenade area, which includes the busy multi-modal Brickell Metrorail station, features wide sidewalks for bus and trolley commuters, a pedestrian path, and a separate bike path between the Metrorail columns, which increases safety, JCFO notes.
Social spaces in the Promenade include a Station Grove, which offers moveable tables and chairs and bicycle parking for commuters; a game area with tables for chess and dominoes; a 50-foot-long communal dining table; and a plaza and stage that hosts activities organized by the Friends of the Underline.
The Oolite Room, named after the Oolite sedimentary limestone of Miami that naturally compresses into ooid forms, frames native plant gardens designed to attract butterflies.
Castilla said: “The Underline is located within the monarch butterfly migration corridor. The park has already seen a resurgence of butterflies that include the Atala butterfly, an endangered endemic South Florida species that thrives with plants such as Coontie and Lantana involucrate.”
As Miami faces climate threats such as extreme heat, sea level rise, and increased ground-up flooding through its limestone landscape, the entire project was also designed to be climate resilient.
To reduce heat gain, Castilla tells us “the project is carefully designed around existing mature trees to preserve them while also carving out sizable new planting areas, minimizing hard surfaces, and, in turn, minimizing heat gain. All hardscapes use light-colored materials. In particular, the bike path asphalt paving was coated with a light-colored finish.”
The landscape architects also made sure the project did its part to reduce flooding from stormwater. “The Underline corridor sits on the Miami Rock Ridge, benefiting from some of the highest elevations in Miami. As such, it is not as prone to flooding or sea level rise as other parts of Miami. That said, we have carefully graded the site to direct all surface water to planting beds in order to minimize direct runoff to the city’s sewers.”