Redevelopment of the waterfront in downtown St. Helens, Oregon, took a significant step forward with a recent ribbon cutting that opens the area to improved public use and future growth. Members of the community gathered alongside project partners to formally introduce the greater accessibility, functionality and public amenities this work delivers.
From left to right: Amanda Owings, Keith Buisman, David Breneman, Mandy Flett
From left to right: Scott Nettleton, Sean Clark, Mandy Flett, Keith Buisman, Amanda Owings
About the Rejuvenated St. Helens Waterfront
In an area that includes several public buildings, like City Hall and the courthouse, the waterfront of downtown St. Helens represented a great opportunity for future growth and expanded public use. After a planning effort led by Otak outlined concept options that include redevelopment of an old mill site, work began on two projects aimed at rejuvenating the area.
The city moved forward with a proposed concept that led to the new riverwalk and its adjacent 1st and Strand roadway. Review of the recommended plans and concepts included input from the community and potential developers to best position the area for both immediate and future use.
Anchored by a circle turnaround that provides a point of interest along the river, the roadway design of 1st and Strand improves access for pedestrians and motorists alike. This includes direct connection to the new riverwalk where Otak worked as a subcontractor to Mayer/Reed to create a new public space ready to host a variety of events.
A number of aesthetic and functional improvements were part of the roadway design, from concrete treatments and bulb-outs with planters at intersections, to a new multiuse path and more clearly defined parking. With an eye on the future, an extension of utilities positions the old mill site for shovel-ready development.
A cornerstone of any growing community is its connectivity. Roadway engineering provides more than just conduits for cars; it forms the framework for mobility in a community that leverages a variety of modes of transportation.
A well-designed transportation network featuring different types of roadways can have widespread impact on economic development and individual wellness. This includes improvements that ensure all areas—especially underserved populations—have access to jobs, essential services, and amenities as well as healthier lifestyles through reductions in emissions and the promotion of active transportation. In this blog we discuss how roadway designs exist at the intersection of planning and transportation engineering to support the growth of healthier, more sustainable communities.
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What is Roadway Engineering and Its Importance?
Roadway engineering is the planning, design, and construction of transportation infrastructure that enhances existing roadways or establishes new connections within a community. The practice integrates technical expertise, urban planning, and environmental considerations to develop safe, efficient, and accessible transportation systems that serve both current and future needs.
The design process starts with an assessment of existing conditions, including topographic mapping, survey and GIS, to understand site constraints. From there, engineers develop roadway layouts that meet design and safety standards. The final design incorporates permitting requirements, cost considerations, and agency coordination to ensure a smooth transition from planning through construction. The end result is a completed roadway that enhances connection across a community.
Stormwater Infrastructure and Low Impact Development
An extremely common aspect of roadway engineering involves the inclusion of stormwater infrastructure considerations. While accounting for increased impervious surfaces and polluted runoff, stormwater features reduce flooding and improve water quality for a community.
With new development comes the potential for negative environmental impact, but proper analysis of natural resources can mitigate adverse effects. Existing culverts are notoriously inefficient and are also among the most common barriers to fish passage. Today, culverts are being replaced to protect aquatic habitat, reduce flooding, and preserve water rights for property owners.
An important piece of roadway engineering is consideration of how it facilitates more than just cars. Multimodal design gives communities options for how they get from point A to point B, all while reducing carbon emissions and promoting physical health through active transportation. Emphasizing pedestrian mobility features like pedestrian bridges, protected bike lanes, cross walks, and traffic stripping reduces traffic conflicts for all.
Safety is the top priority of any roadway project. With updated traffic signals and signage, drivers are more aware, creating a safer environment for themselves and pedestrians. As the design of a roadway considers number of lanes and width, control of speed can also be effectively managed.
A healthy transportation network is a diverse transportation network. As roadway projects increase in size, so do opportunities to incorporate multimodal features. This can include accommodating mass transit with new stations, specialized lanes, or connection to adjacent trail systems. All ultimately contribute to traffic calming, creating a more connected community.
From small neighborhood streets to large arterials, each roadway type must be designed with the specific needs of the community in mind. A critical aspect of any design is engaging with the public to ensure buy-in and minimize disruption. The larger the initiative, the more essential public outreach becomes, and each project presents its own unique impacts to the connectivity of the communities it serves.
Types of Roadways and Their Impact on Communities
Different types of roadways serve unique, though connected, purposes in a transportation network. Their design often begins with comprehensive planning efforts which help identify the transportation needs of a community. Potential projects can then be developed with the focus of serving both community and client goals.
Neighborhood Streets
Neighborhood streets are designed with a primary focus on safety and accessibility, often placing an emphasis on pedestrians, cyclists, and access to public transit. The more limited scope of neighborhood street projects makes cost-effective construction strategies vital to fit within local budgets.
With this localized focus on enhancing connectivity and accessibility, neighborhood streets also typically include ADA-compliant sidewalks and crosswalks while speed bumps or curb extensions are among traffic calming measures. This roadway type requires extra attention to minimizing impact on adjacent properties while maximizing the benefits to those who call the neighborhood home, including the public assets that often exist in the area.
Tualatin, OR Adds Safe Routes to School
Among some of the most important improvements that can be made to neighborhood streets are those that create a safer environment for children that play and travel in the area. For many parents at Tualatin Elementary, it was clear that updates to the neighborhood streets could make a real difference for the kids walking and biking to and from school.
As part of Safe Routes to School (SRTS) programs, which provides grants for these types of improvements, work on 95th and Avery made a variety of upgrades to enhance pedestrian safety, particularly for the kids of Tualatin Elementary.
Multiple intersections were improved with high visibility striping in crosswalks, rectangular rapid-flashing beacons (RRFB), and other features to create safer pedestrian crossings and reduce conflicts with vehicles. Deficient sidewalks and gaps were replaced to further enhance the pedestrian experience.
Mid-Size Collectors and Corridors
Mid-size collectors and corridors serve as vital connections between neighborhoods and larger roadways. This roadway type supports moderate traffic volumes and often incorporates improvements that enhance transportation operations and facilitate flow between developing areas.
Corridors generally aim to improve access to commercial areas, parks, and transit hubs in response to increasing traffic demand. As part of planning efforts, these improvements are sometimes made in anticipation of future development. The larger scope often involves coordination with utility companies and various agencies, as they can have a substantial impact on not only the community but the surrounding environment.
Silverdale, WA Sees Reduced Congestion and an Enhanced Waterfront
The community of Silverdale had long looked to improve on poor waterfront access. Where the Clear Creek Estuary crosses under Bucklin Hill Road and meets Dyes Inlet, high traffic was common which was especially problematic considering its semi-rural setting. Altogether, the area represented a missed opportunity to create an appealing place for recreation, community connections, and growth for local businesses.
Improvements to Bucklin Hill Road and Bridge changed that. Two additional travel lanes eliminated congestion while new bike lanes and facilities were added where there had been none. Widened sidewalks and new trail connections added to new active transportation opportunities for the community. Extensive public outreach, including the “Scout Your Route” campaign to keep the public informed of closures, minimized disruption while reducing construction duration. These improvements had a direct, broad impact on all community members, including residents at senior living facilities in the area that now benefit from greater accessibility to their local businesses.
Large Arterials and Highways
Large arterials and highways are critical for regional mobility, commerce, and overarching economic development. Linking rural and urban areas, these roadways provide communities of all sizes access to important resources like employment and healthcare in metropolitan centers, while supporting the social and cultural networks between different areas. The scale of large highway upgrades can lead to wider improvements to transit-oriented development that diversify modes of transportation and maximize project value.
These roadways often present unique engineering challenges and draw from multiple funding sources, requiring close coordination with agencies to ensure regulatory compliance. As long-term, high-visibility projects, managing timelines and minimizing construction impacts is essential to minimizing disruptions that, at this scale, can be especially costly. This includes effectively communicating project updates with the surrounding community through informational websites, local representatives, and other channels to provide clarity and achieve buy-in.
Salem, OR Supports Rapid Growth and Underserved Areas
In a historically underserved area of Salem, Oregon, where 36% of parcels are underutilized, the McGilchrist Complete Street Project is designed to enhance business development, job creation, and multimodal transportation options for members of the community. It’s part of a 20-year vision for economic growth as well as transportation safety and environmental sustainability.
Considering the large and lasting impact of this work on the community, it was imperative to include them. Extensive stakeholder engagement went above and beyond, working directly with property owners, businesses, and local agencies to ensure the project addressed real community needs. These efforts led to the incorporation of refinements such as the protected cycle track and intersection realignments.
Based on feedback from public outreach, 74% of the corridor features protected bike lanes and new sidewalks. The design aims to significantly improve pedestrian accessibility while minimizing pedestrian-vehicle conflicts, resulting in fewer severe crashes and lives lost. The inclusion of $15 million of stormwater infrastructure upgrades also means this work plays a critical role in not only reducing future flooding for the community but improving habitat for fish.
Making the Complete Connection
Roadways are essential to creating vibrant, connected, and equitable communities. Because of their widespread impact, roadway projects of any size involve a diverse set of considerations to ensure that impact is comprehensive and long lasting. Through thoughtful planning, collaboration, and public engagement, Otak’s multidisciplinary teams take a cohesive approach to designing more connected communities that address current and future needs.
With many disciplines working together on a variety of projects, perhaps the best way to get a feel for a firm’s impact is simply, a coffee with… the people doing the work.
This video series features experts sharing insights gained during their time in the AEC industry, with an emphasis on the importance of collaboration to meet a common goal of creating improved communities.
In this edition, we sit down with a leader of our transportation engineering group and a member of our structural engineering group to hear how their work intersects to create infrastructure that gives people the independence to move.
Find out in the video and its transcript below:
Introduction
Greg: The interface between, you know, roadway and civil and bridges is really about that, that connection of community.
Amanda: Well, that urban built environment was really cool to me too. You know, being able to actually walk through your projects as an engineer drive by.
Greg: ‘I did that,’ right?
Amanda: Exactly.
My name is Amanda Owings. I am the transportation and infrastructure business unit lead for the Oregon and Southwest Washington offices.
Greg: My name is Greg Mines. I am a structures engineer in our bridge group out of Vancouver.
Greg: I mean, bridges are both, you know, literal and metaphorical. So you have, you know, like you’re connecting, you know, connecting communities. And then also, we’ve done a few projects replacing connections that were lost.
Or you’re either trying to help people move through an environment or you’re trying to connect different communities with each other in different areas of community.
Amanda: And adding on to that is giving people options when they don’t have any, right, If they have an alternate way to get somewhere or an independent way to move about their community.
That’s what I think is really heartwarming about the work that we do is that you are now eliminating barriers. You’re giving people independence to move. And that’s something that everybody wants to have. They want that freedom.
Greg: I’ve worn many hats at Otak. I started out doing bridges and then for a while actually went and did some buildings for the national parks. And I get, I get a lot of projects that don’t fit in any particular bin of, of someone’s specialty. So I’ve [done things like] gone scuba diving for projects etc.
I’ve been here for 14 years. But why don’t you kind of fill me in on, on kind of your history with the company?
Amanda: Oh, sure. I started at Otak in 2000. That was my first job out of college. So I was an EIT, worked into my PE as well as project management, and then found that I wanted to try a little bit on the public side.
So for 9 years I was working at two different agencies and really kind of missed consulting, missed the networking, missed working with multidisciplinary teams. So it’s been really nice coming back and being able to work with lots of different people.
Greg: What’s some of the like perspective that you brought from that that public work and, and working for who is frequently our client and coming back again?
Amanda: It’s really helpful to know where their pain points are and what things that they struggle with getting through their councils or through budget or really just working with the public.
So when, when it comes to how a design is put together or how a project is presented, if the public can’t quite understand it then and we need to redesign it. And so I, I have that perspective that’s really helpful just to see it from how the agency is going to be able to pay for it, explain it, maintain it in the future.
What’s it like working closely with the public and local communities?
Amanda: Well, the urban planning side of my work is quite rewarding because it does create projects and work with the communities directly. So the community is really giving their voice to what the design team is working on, and it’s really does make for a much more creative project in the end, and you’re really doing something that the public wants.
One of the communities that I worked in is that there was an intersection that had lots of crashes. It was really unsafe and we worked really hard to get that intersection repaired. And now it’s not even on the safety list and nobody ever thinks about that intersection anymore.
It’s those kinds of things that it’s like, you know, you’ve done a good job when nobody talks about it anymore. A backwards way of finding pride in your projects. But it’s true.
Amanda: We had a project for Washington County, was Olson Rd. And it was one of my very first projects and it had taken almost two years to really get through all the design. There’s like 100 driveways to sign, lots of public outreach.
But that project sticks with me because I can drive it. In fact, I drive it as many times as I can.
The second project that was really rewarding to me was a project in Tigard through their downtown, and we submitted and got a national APWA award for it.
So it was on the cover of the magazine that we really need to see.
Greg: We did one project in Olympic National Park. Crystal Creek Bridge is the name of it, and it was a suspension bridge. It was asymmetrical. It was a design build project. So we’re working with the contractor really closely and making the decisions.
So there was kind of this additional insight that we had during design and it came out and it’s a really cool bridge.
How does your work benefit from a multidisciplinary environment?
Amanda: It is important to work with other disciplines in the industry because it does help you kind of foresee some of the issues that you know are going to be coming. And the more that you can relate with their work kind of makes you design more stuff that much better.
It just goes that much more smoothly.
Greg: Especially early on in a project. I feel like sometimes you’ll get like a maybe a plan set and, and you can tell that it’s not a project yet. It’s four or five individual projects, each discipline kind of doing their own.
And then you start doing that collaboration where you, you sit down and you know, you’re all, if you do a plan sheet turn or whatever, but you trade and then you look at everybody else’s and you’re like, ‘oh, hey, I think we can change this here.’ And then when you start to blend that together.
Amanda: Or asking the questions, ‘why did you do it this way? What can I do to make this a little bit easier for you?’
Greg: And working with the same people you kind of get to know, this is something that, you know, we looked at previously with, with Amanda… she can probably solve this.
The deep bench that we have of that expertise in and, and have it all just in house, You’re just blown away by what you can find.
Amanda: I love that I can pick up the phone and call you anytime when I have a structural question that’s not even related to a project that we’re working on together. But just having that access to you or your team is really helpful to our transportation group.
The Daily Journal of Commerce (DJC) Oregon’s annual event brought together members of the AEC industry to recognize the many accomplishments of women in the field. This year, the DJC Women of Vision Award was received by Kristen Ballou and Sarah Oaks.
Their recognition adds to a growing list of women at Otak that have been honored over the past several years:
2023 – Saretta Tillmaand, Amanda Owings, Margaret Steinhilber
2022 – Millicent Williams
2021 – Tanya Boyer, Rachel Laura, Cathy Kraus
2020 – Serah Breakstone, Tina Keller, Angela Khosa-Marangwanda
Learn more below about each and catch a glimpse of what their peers had to say as part of the nomination process.
Meet the Honorees
Kristen Ballou, Senior Civil Engineer
While designing transportation and utility improvements for communities across Oregon, Kristen Ballou has spent the past 24 years at Otak.
“The successful on-time and on-budget completion of Kristen’s projects was a huge part of the success of the overall Tualatin Transportation bond Program and a huge asset to our city. The success of this program led to voter approval of a similar program for improvements in parks.”
– Mike McCarthy P.E., City Engineer, City of Tualatin
As a senior engineer, Kristen’s most significant accomplishments involve managing and designing detailed projects that provide multi-modal improvements and increased livability to local communities. An emphasis on Americans with Disabilities Act (ADA) guidelines is consistently part of her approach. This includes streamlining development of CAD labeling for ramp design now used by engineers across the organization.
Kristen has also been an active member of the American Public Works Association (APWA), a regular volunteer with the Beaverton School District Art Literacy Program, and a mentor to junior engineers and designers.
Sarah Oaks, Director of Otak CPM
Beginning her career as an AmeriCorps Volunteer at Portland Public Schools (PPS), where she was a founding member of the Office of School Modernization, Sarah Oaks now provides leadership for Otak’s work in comprehensive project management.
“Sarah maintains a sense of stewardship alongside a strong lens of investment in people and culture. She routinely evaluates business growth from a perspective of how to support pathways for professional development of staff, creating a culture of excellence and attraction that people want to continue to be a part of.”
As her career has progressed, she’s continued volunteer and mentorship work with industry groups like the ACE Mentor Program. She has also kept a strong focus on public work, supporting numerous school bonds and central city revitalization efforts. In growing Otak’s PM/CM portfolio across multiple market segments, Sarah has also led a variety of internal initiatives around professional development. From supporting an international exchange program to the implementation a mentorship program, Sarah’s impact has led to stronger ties within Otak’s areas of expertise and has ushered significant growth of individual team members.
Once constrained by by a 585-foot-long railroad bridge, the Dungeness River floodplain was restored while reusing that existing trestle structure to design its river-worthy, salmon-friendly replacement. Located on the Dungeness River at Railroad Bridge Park in Sequim, this multifaceted project supports Olympic Discovery Trail and the broader redevelopment of the Dungeness River Nature Center.
Working with a Local Tribe to Repurpose a Bridge, Reconnect a Floodplain, and Enhance Aquatic Habitats
The restoration and structural design was accomplished in coordination with the Jamestown S’Klallam Tribe with the goal of redesigning multiple features that constrained the floodplain process. Along with the railroad trestle, a parking lot would also be replaced with 350 feet of side-channel and log revetments. Along with levee setbacks, these improvements enhance the local salmonid rearing and spawning habitat. A unique no-rise analysis including two-dimensional hydraulic modeling and large wood stability calculations was used for the dynamic river setting. In utilizing the existing railroad bridge, a unique wishbone approach connects the trails and nature center. From preliminary to final design and preferred alternatives, the Otak team prepared each step of the process including permitting, technical specifications, costs, and bid documentation.
Kevin Dooley (second from left) and other members of the 30th and Colorado Underpass project team accepting the APWA Public Project of the Year Award.
During this year’s American Public Works Association (APWA) event in Atlanta, GA, the 30th and Colorado Underpass was awarded National Project of the Year for its place as a public infrastructure project that promotes excellence in design. After opening a year ago, the project has successfully added safety improvements to a previously dangerous intersection while also advancing the City of Boulder’s multimodal transportation goals.
“This year’s award recipients have shown what happens when you fulfill your commitment to making your community a better place.”
– APWA President Gary Losier, PEng.
The project was also featured during the annual National Association of City Transportation Officials (NACTO) 2023 Designing Cities Conference which was hosted in Denver. Site visits across the area showcased projects that improved access to quality transportation infrastructure, with a particular focus on progressive multimodal networks. Led by our Colorado transportation and structural engineering teams, the 30th and Colorado Underpass joins our list of award-winning work.
About the 30th and Colorado Underpass
At the heart of an essential transportation corridor for the University of Colorado, Boulder campus, the 30th and Colorado Underpass represents the city’s first-ever fully protected intersection. The design places an emphasis on multimodal infrastructure and pedestrian safety. Highlighting lighting, landscaping, and public art features aimed at seamlessly integrating it with the urban fabric.
Pedestrian bridges, also known as footbridges, are vital elements of our communities’ transportation infrastructure. While some are often crossed without much notice, others catch the attention of anyone nearby. In any case, a combination of art and science goes into the design of each structure.
Providing safe passage for pedestrians and cyclists across busy roads, rivers, railways, and other crossings, pedestrian bridges connect communities and enhance overall quality of life through active transportation. But these structures can also serve a greater purpose beyond their practical use, often providing memorable viewpoints, meeting spots, and spaces to enjoy the surrounding environment while making a design statement for communities.
Designed to last for at least 75 years, pedestrian bridges are ingrained in the fabric of the surrounding area and must be resilient to changing environmental conditions to provide long-lasting, accessible, and safe crossing. In this blog, we’ll discuss the steps of the pedestrian bridge design process and key elements around functionality, sustainability, and aesthetics that can make them fixtures of a community for generations.
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What is Pedestrian Bridge Design?
Pedestrian bridge design creates structures that primarily provide safe crossings for foot traffic, cyclists, and other modes of active transportation, facilitating movement between communities and enhancing its surrounding environment.
As trails grow in popularity (including in urban areas), the role of pedestrian bridges in creating accessible, interconnected networks becomes increasingly crucial. Effective pedestrian bridge design can also enhance the usability and safety of trail systems, allowing for uninterrupted and safe passage across both natural and man-made crossings.
The Pedestrian Bridge Design Process
The design of a pedestrian bridge is a meticulous process that begins with a clear understanding of its intended usage and the specific site conditions. This process involves defining the primary purpose of the bridge, gathering detailed site information, creating preliminary designs, and finally, refining those designs into a comprehensive plan for construction.
Define Usage
The first step in pedestrian bridge design is to define its intended use. This includes understanding whether the bridge will primarily serve pedestrians, cyclists, or in many cases even small vehicles. This determines important factors related to load and bridge width. For example, bridges on pedestrian trails are typically four to six feet wide, while those on interurban trails may need to be 10 to 12 feet or sometimes even wider.
Pedestrian bridges often need to support not only foot traffic but also small vehicles such as maintenance trucks, emergency vehicles, or even snowcats. AASHTO guidelines specify that pedestrian bridges must be designed to handle a pedestrian load of 85 pounds per square foot (PSF), with additional considerations for vehicles, where loads can range from 10,000 pounds for maintenance vehicles to 54,000 pounds for emergency vehicles. In remote areas, the design might also need to accommodate equestrian use.
The rise of e-bikes is another growing consideration; while they enhance accessibility, they also introduce new safety challenges due to their speed and weight. Designers have to stay informed about varying state regulations on e-bike usage to ensure safety and accessibility for all users.
Gather Site Information
Once the intended use is defined, the next step is to gather detailed information about the site. This includes conducting surveys, geotechnical analyses, and environmental assessments. The type of crossing — whether over a stream, roadway, or railway — dictates essential design considerations like clearances. For instance, street and highway crossings require a minimum clearance of 16.5 feet, railroads 25 feet, and waterways at least two feet above a 100-year flood event.
Environmental factors such as snow, wind, temperature fluctuations, and seismic activity must also be considered to ensure the bridge’s resilience. This information helps determine the appropriate location and type of abutments, as well as the length, width, and height of the bridge.
Environmental assessments are critical in identifying necessary permits and ensuring that the design minimizes impact on local ecosystems. For waterway crossings, hydrologic and hydraulic analyses provide insights into potential water levels during extreme weather events, guiding decisions about pier placement and scour protection. Other environmental considerations include preventing pollution through stormwater management and minimizing disruption to local vegetation and wildlife.
Preliminary Design and Alternative Selection
Based on the gathered data, preliminary designs are developed by structural engineers, accounting for all client and site-specific requirements. These designs include cost estimates and various alternatives, each with its own set of benefits and challenges. Preliminary sketches and renderings help visualize different options, allowing stakeholders to assess feasibility, constructability, and cost-effectiveness before making a final selection.
Final Design
The final design phase involves detailed structural analysis using specialized engineering software. This step ensures that the bridge can withstand all expected loads, including tension and compression forces. Special attention is given to fracture critical members (FCMs), which are vital components whose failure could lead to the collapse of the bridge. These elements, along with welds, are carefully identified in the structural plans.
With the design configuration set, materials are selected to meet the demands of the environment, such as thermal expansion and slip resistance. Safety and reliability are prioritized, leading to the completion of design and construction documents that detail every aspect of the bridge, from structural components to aesthetic elements.
Types of Pedestrian Bridges
While the majority of pedestrian bridges are either beam or truss structures, there are instances where other options are either required for practical reasons or chosen for design preference.
Beam and girder bridges provide many fabrication and construction options while also being typically more cost effective. Used for shorter spans, they are limited in girder depth and vertical clearance. While they are among the most common in pedestrian bridge design, these structures can be built with materials like steel, concrete, or timber, and can integrate bridge railings to create a unique identity.
With simple construction that installs quickly, truss bridges are another common pedestrian bridge type that offers a cost-effective design. While less unique, a railing that’s integral with the structure can be a fitting aesthetic for many applications. Materials for these structures are generally steel, timber, or fiberglass (FRP).
For medium spans that avoid the use of piers, arch bridges provide graceful aesthetics that can be built low below a trail profile. While more expensive, these structures can be advantageous for greater spans and limiting impact to the environment. They are commonly made of steel, concrete, or timber materials.
Offering a low profile for longer spans, cable stay bridges provide a unique look and feel compared to other pedestrian bridge options, typically showcasing a distinctive fan-like pattern created by their cable placement. Cables can be rigged in a mono, harp, fan, or star design, and similar to most other bridge types can be built with steel, timber, or concrete.
The science of long crossings and art of graceful aesthetics are combined in suspension bridge design. This structure type is especially useful for wide rivers and sites with inaccessible pier locations, often providing a statement for a community using steel, concrete, or timber materials.
Functionality Elements in Pedestrian Bridge Design
Regardless of individual goals, functionality is a core objective in any pedestrian bridge design. In creating a durable, safe, and cost-effective structure that meets community needs for decades, the design should consider a variety of factors. A focus on surrounding pedestrian and bicycle facilities, providing logical routes that encourage use and minimize the need for detours, and consideration of alternative crossing opportunities are all essential to maximizing accessibility and safety.
Wayfinding
A pedestrian bridge is only as valuable as the use it gets. The ability to find one’s way to and from the bridge as part of a broader transportation network is critical to that end.
For effective wayfinding, pedestrian bridge design should integrate with existing transportation infrastructure, ensuring that the bridge is easily accessible and does not require users to travel out of their way to cross. Creating logical connections to surrounding facilities increase the bridge’s utility and enhance the user experience. Additionally, designing a system of cohesive icons and signage not only helps guide users through space visually, but can support tourism, and establish the bridge as a gathering space and community landmark.
Approach Ramps and Accessibility
A sometimes-overlooked aspect of pedestrian bridge design are the approach ramps. Approach ramps ensure that the bridge is accessible to all users, including those with disabilities. The design of approach ramps must adhere to ADA Guidelines, which often require long ramps to accommodate the necessary vertical clearances. Ramps also provide an opportunity to add some creativity in the design that fits within the site footprint. Although these ramps can represent a significant cost, they are essential for ensuring that the bridge is fully functional and accessible.
Abutments and Piers
Serving as the foundation of the structure, abutments and piers can take shape in a pedestrian bridge design in many ways. Depending on the site conditions, abutment design can range from simple footings to more complex anchoring systems.
Geotechnical analysis plays a key role in determining whether deep foundations are necessary, particularly in areas prone to scour. The type and number of piers used also impacts the cost of the bridge relative to its span length.
Sustainability and Resilience Elements in Pedestrian Bridge Design
With a more volatile environment, sustainability and resilience are increasingly critical to pedestrian bridge design. Designers must consider environmental impacts, resilience to climate change, and seismic resilience where necessary. For waterway crossings, hydraulic and hydrologic modeling are essential to ensuring that the bridge can withstand extreme weather events and avoid damaging the surrounding ecosystem. There are a few aspects of bridge design where resilience is particularly relevant.
Stormwater and Drainage
Proper stormwater and drainage design is vital to prevent pollution and maintain the structural integrity of the bridge. Deck drains should be placed at regular intervals to keep the bridge watertight, and curbs should be installed on bridges crossing roads or highways to prevent water runoff. These measures help protect both the bridge and the environment.
Sustainable Materials and Energy Efficiency
The use of sustainable building materials and energy-efficient technologies is an important consideration in modern pedestrian bridge design. Recycled materials and energy-efficient lighting, such as LEDs, can reduce the environmental footprint of the bridge. Landscaping can also promote sustainability by supporting local ecosystems and enhancing the aesthetic appeal of the bridge.
When a pedestrian bridge crosses a waterway, special attention must be given to minimizing its impact on the stream and surrounding wetlands. Regulatory requirements often dictate freeboard levels and the number of piers allowed in the water. Designers must also consider fish passage and scour protection to preserve the natural flow and health of the waterway.
Aesthetic Elements in Pedestrian Bridge Design
While functionality and resilience are paramount, sometimes there is great value – particularly as part of a system of brides – in designing a pedestrian bridge that makes a statement. As integral components of the community, aesthetics can play a pivotal role in an area’s growth. A well-designed pedestrian bridge can become a landmark or gateway, enhancing the community’s identity and appeal. While purely functional bridges are often more cost-effective, investing in aesthetically pleasing features can add long-term value to the community.
The opportunity to consider aesthetics isn’t exclusive to grand design choices. There are a wide range of ways where even small features can have a large, lasting impact.
Bridge System Type
The type of bridge system chosen can greatly influence its aesthetic appeal. Beam and truss bridges are generally more functional, while arch, cable-stay, and suspension bridges offer greater creative freedom, allowing designers to create iconic structures that stand out.
Bridge railings are another element where functionality meets aesthetics. While they primarily serve to protect pedestrians and cyclists, railings can also be designed to enhance the visual appeal of the bridge. In urban or high-risk areas, railings are often higher and more enclosed for safety, whereas in rural areas, simpler designs may suffice. Historical railing systems can be preserved or replicated to maintain the cultural heritage of the area.
Bridge Lighting
Bridge lighting serves both functional and aesthetic purposes. It provides safety for users at night and deters vandalism, while also highlighting the bridge as a visual landmark. LED lighting has revolutionized bridge design, offering energy efficiency, reduced maintenance, and a wide range of color options. The right lighting can transform a pedestrian bridge into a striking feature of the nighttime landscape.
Taking a Multidisciplinary Approach to Pedestrian Bridge Design
Just as one community differs from the next, so do the pedestrian bridges that enhance their connectivity. With a considered process and collaborative approach combing the art and science of each project, the variety of design solutions available offer several paths to both meeting functional goals and making a statement for the community.
As a fixture of infrastructure designed to last decades, pedestrian bridges are created with an eye on the future and resilience in mind. Throughout the design process, input from a multidisciplinary team of engineers, planners, and architects is essential to creating landmark bridge design that maximizes the benefits of these public assets for generations to come.
Providing multimodal access to the city’s growing downtown, the Redmond Central Connector unifies multiple business districts as well as a natural area in the Sammamish Valley across two segments, providing a valuable linkage to the regional trail network. In designing the combined 2.9 miles of trail, Otak also managed construction–finding costs savings to retain project elements–for the phase that included a major connection and vantage point in the historic Sammamish River Trestle.
A Natural Trail Setting Adding Multimodal Connectivity to an Urban Environment
The Redmond Central Connector creates a multiuse pathway that guides users through the downtown urban center to a natural area with views of the beautiful Sammamish Valley. An initial 1.3-mile segment of trail that also retrofitted the Sammamish River Trestle and a bridge over 154th Avenue NE while a following 1.6-mile segment completes a connection between the Cross Kirkland Trail and Eastrail. Together, the trails adapt to and complement different settings, with specific landscape design, lighting, and outdoor art elements implemented throughout. In addressing and treating stormwater runoff, a vegetated collection and flow control facility was added along one portion of the trail. A focus on safety and accessibility includes new ADA-compliant curb ramps to pedestrian and bicycle-friendly retrofits to two bridges. The Sammamish River Trestle was a signature element unifying these urban areas with the river’s natural surroundings and representing a major focus for permitting, shoreline restoration, and critical project timelines during documentation. Set within an existing cathedral of trees in the Willows Run Forest, the trail setting provides a unique getaway from the surrounding urban center to support cyclists and pedestrians, enveloping users into the natural setting that once dominated the valley.
We’re happy to announce the appointment of multiple key leadership roles in our Colorado offices. With new and familiar faces, these individuals will focus on advancing our structural and transportation work as well as the multidisciplinary practice as a whole.
“We’re thrilled to enter this new phase of growth in Colorado. Under the guidance of three outstanding leaders, Otak will continue to expand, innovate, and excel in the Colorado market by delivering exceptional client service.”
With over 30 years of experience, Henry Alaman is a seasoned professional with demonstrated expertise in organizational development, leadership, project management, and business development. Celebrating four years with Otak, Henry has played a pivotal role in the growth and success of the firm’s Project Management and Construction Management (PMCM) division. He has been instrumental in leading key initiatives such as recruitment, onboarding optimization, training programs, and incentive implementations, which have contributed to Otak’s ability to recruit and retain top talent in the industry.
In his own words, Henry expresses gratitude for the support from his colleagues at Otak, stating, “It’s been a humbling experience to be surrounded and supported by such a talented and engaged staff. They have been the collaborative driving force in the progress we’ve made.”
Todd Kelley, Bridges & Structures Business Unit Leader
Bringing fresh eyes and ideas to Otak’s bridges and structures group, Todd has over 17 years of experience in structural engineering design, including: railroad bridges, highway bridges, industrial structures, bridge inspections, and ratings.
With strong analytical and communication skills, his background also includes project and staff management. Todd received his Bachelor of Science in Civil Engineering and a Master of Science in Structural Engineering from the Southern Illinois University. He is a licensed professional engineer in Colorado, Missouri, Washington, Idaho, and California, and a licensed structural engineer in Illinois. Prior to joining Otak, Todd worked for American Rail Engineers in Denver, as General Director of Bridge Design.
Todd expresses his excitement to lead at Otak: “In taking this opportunity at Otak, I was drawn to the experienced people and exciting projects. I’ve found my team to be technically savvy, providing a great foundation for the growth of our group. With plenty of diverse and unique structures, Otak’s approach to projects fits my experience – and where I’d like it to go – perfectly.”
Kevin Dooley, Transportation & Infrastructure Business Unit Leader
Kevin has been with Otak’s Louisville office since 2017 as Transportation Project Manager, contributing his talents to much of the region’s major transportation work including: City of Boulder’s 30th & Colorado Underpass, City of Aspen’s Paepcke Transit Hub, Eagle County’s Eagle Valley Trail, City of Longmont’s Coffman Street Mobility Improvements, and the SH119 (Diagonal) Reconstruction project.
Confirming his confidence in the regional team, Kevin shares, “We currently have the best group of T&I staff that I have seen in my time here. From mentorship and training to the work itself, everyone is already adept at working together very well. This has us set up to provide opportunities for everyone to grow professionally while taking on new technical and managerial challenges.”
Building on more than 17 years of civil engineering experience, including the design and management of complex transportation and civil improvement projects, Kevin’s expertise spans roadway and trail design, drainage, and utility design of local agencies and federally funded projects. His field experience gives him valuable insight into the complete project delivery cycle and his hands-on approach to management and design ensures that projects will have an accurate and reliable set of construction documents. Kevin also participates in Otak’s sustainability leadership group, assisting with green initiatives in the company’s practice areas and training.
“The Colorado Region leadership has never been as strong and engaged as the team we have in place now… Their focus on client care, high quality, timely service delivery, solving for our clients, and mentorship skills makes me confident in their ability to develop the best team possible in our market.”
– Scott Dreher, COO of Otak
Otak is excited to continue generating momentum for our work in the Rocky Mountain region with the addition and promotion of top talent. The company is eager to see Henry, Todd, and Kevin thrive as leaders and develop project work and partnerships with key regional clients.
A corridor study led to the complete streets design along a key arterial with high crash trends, adding greater safety and connectivity to the communities around Boulder, Colorado. The improvements to 30th Street focused on enhancing bicycle infrastructure as well as access to mass transit and low-impact design stormwater facilities. After completing the Colorado Corridors Study, Otak also led the design to improve this corridor that represents a critical route for both University of Colorado boulder and broader community.
A Corridor Study and Design for Safe, Complete Connectivity
A combination of raised and separated bike lanes, along with widened sidewalks provided the basis for multimodal improvements along 30th Street as part of the city’s ‘Vision Zero’ goals to eliminate pedestrian collisions. The design replaced previous on-street bike lanes that were five feet wide or less and addressed intersections that were found to be among the top collision locations in the city by the corridor study. These new bicycle facilities created seamless connection to the Boulder Creek Multi-Use Path, enhanced transit stops, as well as the 30th and Colorado Underpass. Also included as part of the complete streets design approach were improved driveway and ditch crossings, utility upgrades, low-impact stormwater facilities, and low-maintenance landscaping with a modified irrigation pipe system. A significant urban street tree canopy and resilient landscape areas further enhanced safety by creating a buffer between the bikeway and traffic lane while also serving as water quality elements for stormwater. The design effort resulted in the delivery of final construction documents in accordance with the City of Boulder and CDOT standards, along with obligations related to CDOT Federal and State-funded Local Agency project requirements. Significant public outreach and coordination with the University of Colorado was part of the original corridor study that ultimately provided guidance across these multimodal enhancements.
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At the heart of an essential transportation corridor for the University of Colorado, Boulder campus, the 30th and Colorado Underpass represents the city’s first-ever fully protected intersection. The design places an emphasis on multimodal infrastructure and pedestrian safety. Highlighting lighting, landscaping, and public art features aimed at seamlessly integrating it with the urban fabric.
