"Green" Construction Practices
TriMet has a commitment to protecting the environment that ranges from business and vehicle operations to maintenance facilities and construction initiatives. This commitment, which began with the construction of Interstate MAX Yellow Line, continued with the construction of MAX Green Line in downtown Portland, along I-205 and most recently with the completion of WES Commuter Rail.
- Reuse and recycle
- Storm water management
- Reduce energy and vehicle emissions
- Eco-friendly construction
Reuse and recycle
Plastic railroad ties
TriMet was the first to use recycled plastic railroad ties in embedded light rail trackway.
Instead of using steel, the MAX Yellow Line used 6,000 plastic ties made of recycled plastic automobile gas tanks.
Creosote ties
During construction on WES, a portion of the removed creosote ties were sent to an energy co-generation plant, saving landfill space. The remainder of the ties were reused in the project as landscaping elements.
Concrete
Approximately 30,000 cubic yards of concrete, existing aggregates and base material were crushed or cleaned and reused on the construction of the MAX Green Line.
Plastic bollards
MAX Yellow Line was the first to use recycled plastic bollards in paved portions of the trackway. The bollards and the recycled plastic chain discourage pedestrians from crossing the trackway.
Sound walls
TriMet relocated approximately 1,810 feet of existing sound walls and installed nearly one mile of new sound walls along the 1-205 light rail line. For this purpose, TriMet selected a unique product with a composite plastic shell filled with recycled, chipped tires. Manufactured by Carsonite, the new sound walls diverted a total of 9,030 tires from the landfill.
Stormwater management
For decades, virtually all surfaces along freeway corridors have been impervious, allowing water runoff from the roadway to flow directly into stormwater systems, area streams, creeks and rivers.
Along freeway corridors, TriMet created vegetated bioswales to filter and slow stormwater runoff. In areas where the soil is less pervious, TriMet implemented creative solutions such as partial water retention measures. In addition, parking areas at some of the MAX Light Rail systems-support buildings utilize pervious pavement to reduce runoff.
MAX Yellow Line at Delta Park/Vanport Station
TriMet built a pond with plantings and artwork to collect and naturally clean stormwater runoff from the Park & Ride lot.
MAX Yellow Line at N Prescott St Station
A tall sculpture suggestive of a ship's prow at the N Prescott St MAX station gathers rainwater and funnels it to a drain leading to the nearby bio-filtration greenspace.
WES Commuter Rail at Beaverton Transit Center
Restoration for the Hall and Beaverton creeks was done through the planting of native trees and the removal of invasive plants such as Reed Canary Grass.
MAX Green Line from Market Street to the South Terminus
TriMet added landscaping that includes planting strips and bioswales for water filtration to treat the stormwater from the street, tracks and light rail operations. Water treatment planting strips accompany the new extension of the brick from Market Street to the South Terminus.
Reduce energy and vehicle emissions
Improvements to track
Upgrades on WES Commuter Rail train tracks help improve Portland & Western's capacity to move frieght with greater fuel efficiency.
Learn more about conserving fuel and reducing emissions
Eco-friendly construction
Trees–MAX Yellow Line
TriMet tripled the number of trees along Interstate Avenue, and numerous large trees were relocated in the area.
Neighbors helped select the size and type of tree species to be planted. Naturescaping principles are applied when selecting plantings that could survive in an urban environment using less water, fertilizers and pesticides.
Trees–MAX Green Line
Tree preservation along 5th and 6th avenues and I-205 was a project priority. Although light rail construction required the removal of trees, the project ultimately planted over 1,100 new trees. New trees were chosen to thrive in the specific environment in which they were planted. Several of the removed trees were salvaged for use in furniture and residential structures, while others were used as bark mulch.
Wetlands
TriMet expanded and recreated the wetland next to the Forebay Slough on Portland International Raceway property.
About 18,000 cubic yards of soil was excavated to allow the newly restored wetland and the Forebay Slough to become one continuous body of water. TriMet enhanced the wetland by planting more than 200 trees, 12,000 deciduous shrubs and 12,000 plants. The wetland provides wildlife habitat and the ability to bio-cleanse the water.
Earth-friendly buildings
New facilities that support the maintenance and operation of the MAX Yellow Line were built with an environmental focus.
- TriMet's systems-support buildings were designed to shed rainwater and let it percolate into the ground rather than entering the storm sewer system.
- TriMet's expanded maintenance facility at Ruby Junction was designed using earth-smart elements that are 20 percent more efficient than current energy code requirements. The new building uses energy-efficient lighting and variable air volume mechanical systems.
Wildlife
Along the WES alignment, north of Wilsonville, a wildlife crossing was installed under the tracks to maintain a safe passage for animals.
