Herrera’s Innovative Trail Design for Lewis & Clark College

Located in Portland, Oregon, Lewis and Clark College is a private liberal arts institution spanning 137 acres in the Collins View neighborhood. For several years, pedestrians have used an informal, unpaved trail at the edge of a steep ravine to travel between Tri-Met bus stops and the Lewis & Clark College Law School. Concerns around trail accessibility and safety pushed the College to find a way to improve trail usability. In 2016, Herrera took on the task to relocate two transit stops on SW Terwilliger Boulevard. Through this project, Herrera’s interdisciplinary team designed and permitted trail and sidewalk extensions and transit waiting areas for the proposed bus stop locations. Herrera is proud of our work in providing Lewis and Clark College with a sustainable solution to improving trail user safety and accessibility, while preserving the site’s ecological features.

Design Concept

At the beginning of Herrera’s collaboration with the College, the design plan centered around replacing the trail with one designed to meet standards of the Americans with Disabilities Act (ADA). When researching permit requirements for the City of Portland, Herrera discovered City-designated environmental overlay zones within the project site. With this, Herrera deemed the initial design concept infeasible, as ADA standards could not be met in the trail’s current location. To solve this issue, Herrera proposed working with Tri-Met to relocate the bus stops and extend sidewalks within the right-of-way to improve pedestrian access. With an alternative plan in place, Herrera began its conceptual design of sidewalk extensions to connect existing sidewalks with proposed transit stops on both sides of SW Terwilliger Boulevard.

On the north side of street, the pedestrian way and curb extend westward from existing sidewalk to proposed transit stop. The proposed bus stop location includes a 10-foot-long by 7.5-foot-wide, solid concrete pad with a standard curb. On south side of Terwilliger Boulevard, a 10-foot by 10-foot concrete pad makes up the proposed transit stop and is built adjacent to the end of the existing sidewalk. At Tri-Met’s suggestion, the pavement extends westward from the transit stop to improve access for people exiting from the rear of the bus.

Herrera’s conceptual design conforms to the 2010 TriMet design standards, current City of Portland standards, and the design standards of the Americans with Disabilities Act (ADA), to the extent feasible. In addition to following these standards, Herrera’s team tailored this design to avoid affecting existing trees and infrastructure, minimizing environmental impacts.


Located within a City-designated scenic resource zone, the proposed project area includes landscaping and tree preservation requirements and limits on pedestrian areas. With all proposed project elements within the street right-of-way, Herrera obtained a City Limited Public Works Permit from Portland Bureau of Transportation to start work within the project site. In addition, Herrera coordinated with the Portland’s Urban Forestry Division to confirm applicable standards of Title 11 as it relates to tree preservation and planting. Based on the need to remove street trees as part of the project design, Herrera prepared a Tree Plan and application for a City Tree Permit to allow for removal, alteration, and the planting of trees on the project site.

This project exemplifies Herrera’s innovative design approach, dedication to improving resource efficiency, support of healthy habitat, and enhancement of our Portland community.