Revitalizing the Cheonggyecheon Stream
The Cheonggyecheon restoration project was centered on revitalizing the Cheonggyecheon Stream that had been covered for decades by a highway overpass. The city of Seoul used its own resources to bring new life to the downtown by enhancing the urban environment. The restoration of the Cheonggyecheon Stream led to the revitalization of central Seoul, unleashing the potential for green public space.
Stream Street:
Managing stormwater: Transformed, Public, Ecologically Restored Green and Blue Space
System(s):
Natural
Street Type:
Thru Street, Some Activity
Street Design Objectives
- Flood protection
- Provide space for plantings, trees, and other landscapes for aesthetic and ecosystem services, i.e. biodiversity
- Accommodate movement of cars, trucks, and bikes through separated mobility lanes
- Address air pollution
- Address heat island concerns
- Continue to support mixed-use, commercial activities
Street Design Geometries
- Street widths is 164’
- From 10 lanes to four lanes of traffic
- Separated bike lanes within green / planted canal buffers
- Shared mixed traffic lanes
Street Design Program
- Removal of elevated highway
- Daylight historic stream - canal restoration
- Extensive new open spaces, including green infrastructure
- Bridges to reconnect areas across street
- Accommodate car sharing, truck deliveries, and unloading / loading
Street Design Materials
- Site / park-like furniture
- Daylighted canal
- Concrete / asphalt sidewalks and streets
- Trees, plantings, soil
Costs
- $345,000,000
- Funding by Seoul Metropolitan Government
Political, City, Agency Leadership
- Central Government, Seoul Municipality, Seoul Metropolitan Government, Cultural Heritage Administration, Cheonggyecheon Research Group, Citizen’s Committee for Cheonggyecheon Restoration Project, Seoul Development Institute urban design team, Dongmyung Eng, Daelim E&C
- Close to 4,000 meetings were held with residents; A “Wall of Hope” program was developed to encourage involvement and resulted in 20,000 participants
- Operations, Management and Maintenance entities and requirements
Monitoring Successes
- The project contributed to a 15.1% increase in bus ridership and - 3.3% increase in subway ridership between 2003 and 2008
- The revitalized street now attracts 64,000 visitors daily
- 76% increase in pedestrian activity
- 4.5% reduction in heat island effect
- 45% decrease in vehicle volume
- 10.3T% decrease in air pollution
Comparable NYC Streets
- Many wide streets in NYC, highways, and truck routes - preferable streets along lower contours of the City and/or streets that have slope to move water
- Some Activity Streets that can accommodate deliveries at off-peak times
- Street with excess cloudbursts and flooding
Strengths of Study for NYC Context
- Environmental benefits along high-traffic roads, including truck routes
- Stormwater management
- Social / community gathering opportunities in the street
- Diversity in mobility
- Promotes public transit
Challenges for NYC Context
- People in NYC already have high public ridership - would need to consider how to reduce commercial traffic - congestion pricing, etc
- Capital costs - possible public private partnership opportunities
- Maintenance for more enhanced plantings / landscape and canal
Critical alternative transportation for the city of Portland
Portland’s neighborhood greenways are a series of connected residential streets designed to prioritize bicycling and enhance conditions for walking. They function as critical alternative transportation for the city of Portland by creating safe streets where people want to bike, walk and play. To date, Portland has more than 70 miles of neighborhood greenways.
Neighborhood Greenway Street:
Safe, Continuous Cycling and Pedestrian Space
System(s):
Community, Transportation
Street Type:
Residential, Some Activity
Street Design Objectives
- Reducing space for vehicles. If there aren’t better travel options, there will be an additional 110,000 cars on Portland streets by 2035, a 54% increase
- Increase safety and usability of streets for exercise and transportation
- Supporting climate goals and building healthy communities
- Traffic calming
Street Design Geometries
- Speed bumps
- Protected crossings at busy streets
- Traffic diversions (physical barriers)
- Wayfinding signs
- “Sharrow” street markings
Street Design Program
- Rain garden infiltration areas
- Cross-street closures to decrease automobile traffic
- Bike lane buffer protection at intersections
- Median islands to decrease pedestrian crossing distance
- Speed bumps to slow down traffic
- Shared streets
Street Design Materials
- Trees, soil, and perennials (including pollinators)
- Street markings
- Signage
Policy, Codes, and Guidelines
- Vehicles should travel 20 mph or less
- There should be a daily average of approximately 1,000 cars per day with the upper limit set at 2,000 cars
- There should be ample opportunities for people bicycling and walking to cross busy streets
- 50 crossing opportunities per hour, with 100 crossing opportunities per hour the preferred level of service
Comparable NYC Streets
- Most Residential Streets
- Some Activity Streets with less commercial uses
- Street that run perpendicular to City parks and open space
Strengths of Study for NYC Context
- Stormwater management
- Social / community gathering opportunities in the street
- Bike lane connectivity and safety
- Safe pedestrian crossings
Challenges for NYC Context
- Pedestrian safety for shared street
- Maintenance for more enhanced plantings / landscape
- Policies for changing the traffic speed in certain districts
- Width of street to keep parking and shared bike lanes
- Traffic pattern changes to account for re-routing traffic routes
Additional Benefits
- Porous asphalt in the bike lanes, roadways
An adaptive city-wide solution for managing stormwater
With costly intense precipitation events known as “cloudbursts” already stressing the city infrastructure, the City of Copenhagen developed an adaptive city-wide solution for managing stormwater and reducing flooding risks. The Plan focuses on city-wide connected streetscape and public space solutions that combine large-scale, blue green infrastructure projects that manage stormwater at the surface with underground drainage tunnels where needed.
Neighborhood Stormwater Street:
Porous, floodproof, Ecosystems Services
System(s):
Stormwater, Ecology
Street Type:
Residential, Activity, Thru
Street Design Objectives
- Urban biodiversity enhancement
- Social infrastructure
- Increasing permeable area
Street Design Geometries
- Increased vegetated area wherever possible
- Separated pedestrian and multi-use paths
- Wide paths for seating areas
- Protected crossings at busy streets
- Stormwater infiltration areas
Street Design Program
- Rain garden infiltration areas, plant biodiversity
- Bike lane buffer protection at intersections
- Median islands to decrease pedestrian crossing distance
- Multi-use paths separated from automobile traffic
Street Design Materials
- Trees, soil, and perennials (including pollinators)
- Street markings
- Pedestrian islands
Costs
- $278,000,000
Political, City, Agency leadership
- City of Copenhagen, Center for Climate adaptation
Comparable NYC Streets
- Residential, Activity, and Thru Streets
Strengths of Study for NYC Context
- Stormwater management
- Enhanced ecological corridors
- Social / community gathering opportunities adjacent to habitat areas
- Bike lane connectivity and safety
- Safe pedestrian crossings
- Designed for 100 year storm
Challenges for NYC Context
- Sight lines for lush vegetation
- Capital money for large-scale street reconstruction projects
- Policy changes to make green infrastructure solutions part of standard practices for DOT, DEP and other NYCDPR
- Pedestrian safety
- Maintenance for more enhanced plantings / landscape
- Width of street to accommodate vegetated areas and multi-use paths
Additional Benefits
- Porous asphalt in the bike lanes, roadways
- Speed bumps to slow down traffic
A greener, pedestrian-friendly central grid
Over the next decade Barcelona will expand its current Superblock Program and convert its entire central grid into a greener, pedestrian-friendly area almost totally cleared of cars. The Superblock Plan requires that vehicle traffic be permitted only around the perimeter, leaving streets within the district only accessible by motor vehicle to residents, essential services or deliveries.
Neighborhood Active Street:
Safe, Active, Community Streets
System(s):
Transportation, Open Space
Street Type:
Residential, Activity
Street Design Objectives
- Fewer cars
- More space for adjacent businesses to extend outdoors, including outdoor dining
- Permeable pavement
- Decorative pavement
- Tree planting
- Separation of pedestrians and minimal car traffic and parking
- More space for pedestrian activities and programming
Street Design Geometries
- Street widths vary
- Reduce or removed vehicle lanes
- Separated bike lanes
- Plazas and other gathering spaces created at intersections
- Shared mixed traffic lanes
- Removal of curbs
Street Design Program [varies]
- Shared streets
- Plazas and parklets
- Separated bike lanes
- Shared bike lanes
- Enhanced planting
- Outdoor furniture
- Street marking - artistic
- Raised planters
- Public art
- Comparable NYC Streets
- Activity Streets, including commercial and retail streets
- Residential Streets that include retail or commercial on the ground floor.
Strengths of Study for NYC Context
- Ability to include street and shade trees in a relatively narrow planter using structural soil
- Stormwater management from the porous pavement
- Encourages local businesses and outdoor eating, working, gathering
- Offers opportunity for different modes of mobility
- Could accommodate limited car /truck access while providing many more opportunities for pedestrians
Challenges for NYC Context
- Political will to reduce car traffic on activity streets
- Less parking available for commercial and/or residential use
- New planting and porous pavement strategies are not currently standard practices for NYCDOT and/or the NYCDPR.
- Enhanced maintenance for porous streets and planting
- Maintenance and operations for new plazas and parklets created by the Superblocks
The UK’s largest inner city ‘Green Street’
The “Grey to Green” scheme in Sheffield is the UK’s largest retro-fit SuDS project, and also the UK’s largest inner city ‘Green Street.’ The scheme has been implemented along the length of an inner-city dual carriage-way, which runs along the edge of Sheffield city center. Traffic lanes were removed and given over to extensive areas of rain gardens and bioswales, and widened pavement spaces for pedestrians. One of the main functions of the scheme is to reduce and slow down surface-water runoff. In 2007 the whole of this part of Sheffield was flooded, causing major disruption and economic damage. The grey to green scheme is designed as part of a wider strategy to reduce the amount of surface-water runoff reaching the River Don.
Green Street:
Wild, floodproof, porous
System(s):
Stormwater, Ecology
Street Type:
Residential, Activity, Thru
Helping make London’s diverse communities greener, healthier and more attractive places
The Healthy Street / Healthy People initiative in London aims to improve air quality, reduce congestion and help make London’s diverse communities greener, healthier and more attractive places to live, work, play and do business. The Plan outlines some practice steps: Improving local environments by providing more space for walking and cycling, and better public spaces where people can interact; Prioritizing better and more affordable public transport and safer and more appealing routes for walking and cycling; Planning new developments so people can walk or cycle to local shops, schools and workplaces, and have good public transport links for longer journeys.
Neighborhood Healthy Streets:
Safe, Sustainable Community Streets
System(s):
Public Space, Transportation
Street Type:
Residential and Activity
Street Design Objectives
- Reduce the amount of space for vehicles to accommodate other programming / amenities
- Provide space for plantings, trees, and other landscapes for aesthetic and ecosystem services
- Accommodate car sharing, truck deliveries, and unloading / loading
- Traffic calming
- Block-wide waste disposal
- Shared streets
Street Design Geometries
- One traffic shared lane
- Curb-cuts
- Traffic calming “bump-outs”
Street Design Program
- Removal of parking for most of the blocks
- One to two parking spaces at the ends of the block, on one or both sides of the street
- Rain gardens and bioswales installed towards the lowest elevations of each block
- Mid-block waste receptacle enclosures for trash, compost, and recycling collection
- Accommodate car sharing, truck deliveries, and unloading / loading
- Slow down traffic
- Block-wide waste disposal
- Shared streets
Street Design Materials
- Bike racks
- Raised planters with integrated seating
- Concrete / asphalt sidewalks and streets
- Trees, soil, and perennials (including pollinators)
- Trash receptacles
- Street markings
- Signage
Comparable NYC Streets
- Most Residential Streets that do not include commercial or retail space on the ground level
- Some Activity Streets that can accommodate deliveries at off-peak times
Strengths of Study for NYC Context
- Communal waste station / receptacle
- Stormwater management
- Social / community gathering opportunities in the street
- Bike amenities - racks
- Spaces for loading, delivery and short-term parking
Challenges for NYC Context
- Significant reduction in parking. This type of street vision requires policies that limit the number of cars in certain districts and/or the construction of garages / infrastructure to accommodate neighborhood cars. The increase cost in parking a car in the city due to a reduction in free street parking may be
- Costs associated with shared waste receptacles - including maintenance
- Pedestrian safety for shared street
- Maintenance for more enhanced plantings / landscape
- Regulating the short-term parking spaces
Read the Report
Re-envisioning the Right-of-Way
Acknowledgements
Authored by
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Tricia Martin
Local Office Landscape and Urban Design, Associate Principal
-
Ana Piacentini
Local Office Landscape and Urban Design, Senior Designer
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