The City of Milwaukie’s SAFE program aims to improve the safety of pedestrians and bicyclists by upgrading the city’s network of sidewalks, ramps, and crossings. The 43rd Avenue SAFE/SSMP Improvements project brought much-needed pedestrian and bicycle safety improvements to this largely residential neighborhood whose residents had been vocal about needing sidewalks, ramps, and crosswalks. Due to narrow right-of-way and tight budget requirements, each element of this project was custom designed to capitalize on existing infrastructure, manage stormwater, avoid impacts to established trees, and integrate more than 40 driveways into the new cross-section.
Century West was the engineering consultant for the project, from alternatives analysis through final design and bidding. Services provided for the project include:
- Project management;
- Organize and attend public involvement meetings;
- Conceptual and final design for sewer, stormwater, sidewalk, ADA, and roadway improvements;
- Utility coordination;
- Construction documents;
- Bid support; and
- Construction administration support.
The design team included subconsultants JLA Public Involvement (Public Involvement), NV5 (Infiltration Testing), Shannon & Wilson, Inc. (Geotechnical Engineering), Westlake Consultants, Inc. (Survey); Tapani Inc. (Contractor).
Unique Application of Techniques
The goal of the City’s SAFE program is to improve safety for people walking, biking, and more. SAFE calls for upgrading the City’s network of connections, such as sidewalks, ramps, and crossings to fill network gaps, replace portions that don’t meet ADA standards, and remove barriers for people to get where they need to go safely.
Residents on 43rd Avenue have been vocal about their support for multimodal improvements on their street since the inception of SAFE. As a minor collector street, 43rd Avenue connects the neighborhood to Safeway and the Tri-Met bus line on King Road and sees students walking home from nearby Seth Lewelling Elementary School. The area also sees significant bicycle activity due to Milwaukie’s network of bicycle paths, though no such paths existed on 43rd Avenue. The intersection of 43rd Avenue and Howe Street was particularly dangerous due to the high speeds.
Limited right-of-way on 43rd Avenue made the traditional cross-section of a bicycle path and curbed sidewalk on both sides of the street impractical. The City and Century West worked through multiple alternatives early in the project to identify a solution that would provide the community with what it needed: a safe, separated facility for bicyclists and pedestrians. The chosen solution was a 10- foot pervious asphalt shared-use path on the west side of the road and a sidewalk on the east side. The wide path is easier to use for children and people with mobility issues versus a typical five foot sidewalk. Directional markings appear on the path to separate pedestrians and bicyclists, and sharrows are present on the roadway to encourage cars to slow down and watch for bicyclists. Other enhanced features include ADA ramps and crosswalk markings at side streets.
Enhanced Public Awareness
The community was involved in the initial development of the SAFE capital improvement program list. Public involvement specific to the SAFE program was a rigorous, multi-year process to identify those projects that would be most impactful to multimodal safety.
Specific to this project, the City and Century West held two open houses: one in the concept design phase and one for pre-construction to discuss impacts during construction. For the duration of the project, design concepts were hosted online. Nearly every driveway required a customized design to tie in with either the multi-use path to the west or the sidewalk to the east. Century West met with select priority owners whose driveways were particularly challenging due to specific uses or unconventional configurations.
Social, Economic, and Sustainable Development Considerations
Low-Impact Development Approach to Stormwater A variety of stormwater applications were used on this project, including the re-use of existing dry wells, addition of stormwater planters, new stormwater conveyance system, and a new pervious multi-use path. 43rd Avenue, which comprised the majority of
this project, is designed to fully treat and infiltrate the 25-year stormwater event on-site.
Variable Depth Grind/Overlay Rather than a typical reconstruction that would pull out existing rock and asphalt and replace it with new material, the project team used variable grind and inlay techniques to change the shape of the street to allow for stormwater drainage and make room for
the sidewalk. This technique required applying more pavement to the roadway in certain areas but made the best use of the existing material.
Tree Preservation and New Landscape As described in more detail in the next section, this neighborhood has many well-established trees that were saved to the extent possible during design and construction. The project also planted new trees that support the character of the neighborhood.
Air Spading The project team used air spading to verify tree root extents and reduce impacts. Open aggregate was specified in tree well locations to allow for drainage so that water is not sitting on top of tree roots causing rot. On Howe Street, the design originally called for the removal of five trees, but changes suggested by the contractor during construction resulted in removal of only one tree in this area. These large trees provide shade, heat reduction, and stormwater benefits that made the adjustment well worth the time and effort. Century West also suggested the addition of City-approved landscape trees in pockets of unused right-of-way, which resulted in planting an additional 38 trees throughout the project area.
Complexity
The 43rd Avenue Improvement project is a lesson in custom design. Rather than pointing to a past project and regurgitating the design, this project’s limited right-of-way forced the team to be creative in meeting the community’s needs. Particularly complex aspects of the project included:
• Staying in budget while customizing design for each driveway, integrating new stormwater solutions into the existing system to the extent possible, and carefully creating specifications for the unique grind needed to obtain the desired roadway profile.
• The solution of the meandered path is not typically seen in an environment as urban as 43rd Avenue. This atypical application allowed the project to stay within the existing right-of-way, which was a major goal of the project.
“When I have been on-site during construction, I have had residents come up and thank me for the work we’ve done. This community is composed of quite a few residents who have lived here a long time. They tell me how much they love having these amenities.”City Project Manager, Jennifer Garbely, PE
This project is an excellent example of engineering ingenuity in tight right-of-way conditions on a limited budget. Century West listened to what was important to both residents and the city of Milwaukie and customized solutions to meet those expectations. 43rd Avenue now provides safe connections for pedestrians and bicyclists to access nearby schools, grocery stores, and other neighborhood amenities.