Pedestrian bridges can be beautiful as well as functional, but we often get asked: how long do they take to install? Another question we hear a lot is, “how long does it take to build a bridge over water?” These are not easy questions to answer as several variables can influence a bridge timeline. For instance, even a simple thing like the depth of water, shallow or deep, can affect the timeline of installing a pedestrian bridge over water.
The short answer is that the final step of unloading, assembling, and installing a pedestrian bridge usually takes between two and four days to complete on average. Installation is quick because pedestrian bridges are usually fabricated at a manufacturing facility and transported to the site on trucks. In fact, the process can sometimes be completed in a single day if the abutments are already in place and the terrain is not challenging.
Steps for Installing a Pedestrian Bridge
Pedestrian bridges are usually installed for public use to span the gap, allowing people to cross over when they are walking, cycling or horseback riding. Also, they make crossing highways, railroad tracks or natural obstacles like streams or rivers safer and more enjoyable.
While vehicle bridges that carry tractor-trailers weighing up to 40 tons take years to design and build, pedestrian bridges can often be put into service in just a couple of months. This process usually involves the following four steps:
- Design and planning
- Reviewing and approving the plans
- Installing the bridge abutments
- Installing the foot bridge
Bridge Design and Planning
Plato once said, “the beginning is the most important part of the work,” and this is particularly true when embarking on an engineering project like installing a pedestrian bridge. Mistakes made during the planning stages can cast very long shadows indeed, so it is wise to consider all available options before deciding on a plan of action.
A bridge design and construction company’s first step is meeting with the client to determine their needs and priorities, e.g., bicycle bridges, safe routes, two-way design, middle sections, and location. There may even be discussions about the materials that make up structures, such as concrete decks or wood.
Once this is accomplished, the company designs and plans a structurally sound and safe bridge that meets these goals. The design stage usually lasts between six and eight weeks.
How Wide Will the Bridge Be?
One of the first decisions in the design process is choosing the width of a walking bridge. This will be largely based on the anticipated foot traffic and whether or not the structure will be used by cyclists and ATV riders as well as pedestrians.
Pedestrian-only bridges are usually about four to six feet wide, depending on features like the feet of boardwalk needed or a barrier-free pathway design. In comparison, pedestrian bridges that also accommodate light vehicles should be at least eight feet wide.
What Kinds of Traffic Will Cross the Bridge?
The anticipated traffic on a pedestrian walkway bridge will influence its basic design as well as its width. Bridges that carry light vehicles require more robust construction, which could rule out aesthetically pleasing designs like arch bridges.
Account for the Terrain
Experienced construction companies obtain geotechnical reports before designing pedestrian bridges. These reports reveal the soil conditions at the site and determine what kind of foundation the bridge will sit on. If the soil is excessively wet and not capable of supporting the planned bridge, deep foundations may be required, but typically compacted gravel can be used to create a firm base.
Design Drawings: Reviewed and Approved
Companies like Axcess can build and install truss, beam, arch, and suspension bridges, which means they can offer their clients several design options to choose from.
After the client settles on one of these options based on cost and aesthetic considerations, final design drawings and plans can be drafted for their approval. After the plans have been reviewed and accepted, the client will have what they need to obtain the necessary permits. This process may involve dealing with several regulatory agencies.
Allow Four to Eight Weeks for Design Production and Approval
Drafting, reviewing, revising, and approving pedestrian bridge designs usually takes between four and eight weeks to complete. However, securing approval to begin work can take longer when the site is complex, costs are higher than anticipated, or several companies are asked to submit design proposals.
Installing the Abutments
Bridge abutments serve two primary purposes: 1) they support the ends of a bridge and 2) they connect the structure with the trail, path, or sidewalk leading up to it.
Installing abutments can be accomplished fairly easily using precast concrete blocks if the bridge is short and elevating the walkway is not required.
If the job is more complex and may involve casting concrete foundations at the site or driving piles when bridges are larger.
Allow Four or More Weeks for Abutment Install
Abutments provide vertical support to the bridge, which means taking shortcuts here can lead to catastrophic problems later on. Simple pedestrian bridge abutments can usually be installed in about four weeks, but the process can take longer if the bridge is large.
Final Installation of Your Pedestrian Bridge
The final pedestrian bridge installation can be completed quickly and efficiently if the design is sound and the people doing the work have the proper equipment and training. Here are the steps involved:
- Site assessment: Before the bridge is shipped from the manufacturing facility, professionals visit the site to check for environmental challenges and make sure that there will be enough space for large trucks and lifting equipment to operate.
- Shipping: Pedestrian bridges are usually shipped in sections to the site on large trucks. Cranes or excavators are then used to unload the bridge sections and move them into place.
- Assembly: Installation crews are given detailed build sheets that tell them how much each bridge section weighs and how all the sections fit together.
- Finishing touches: Before the installation crew leaves the site, they check that the bridge is stable and secure and clean up any debris.
Allow Up to Four or More Days for Final Installation
Installing a simple pedestrian bridge only takes a day or two because most of the problems that could cause long delays are identified and addressed during the planning stages. The process is sometimes a little more involved, but even complex bridges can usually be installed in a few days.
How to Build a Pedestrian Bridge
Road bridges take at least two years to build and are paid with general fund money. Sometimes though, the work can sometimes drag on for more than a decade. On the other hand, pedestrian bridges are much easier to design and construct because they are smaller, require less permitting, and are easier to design.
Bridge Construction Timeline
So what’s the total time that it takes to build a bridge for pedestrians? The timeline to construct it will vary based on factors like the size of the bridge (the amount of bridge spans, additional boardwalk sections, etc.). Also, factors like universal access for foot traffic, materials, and the land where it will be installed, factor in the timeline.
If you are planning a simple pedestrian bridge, you can expect:
- The design, planning and approval stages to take between six and eight weeks.
- Installing abutments to take at least four weeks.
- Final installation and site clean-up to take between two and four days.
Bridge Construction Process
Most pedestrian bridges are built at construction facilities and shipped on large trucks. The abutments that support them and hold back earth at the approaches are made out of concrete, and the load-bearing elements that connect the abutments are made out of concrete or steel.
Deck materials like fiber-reinforced polymers (FPR) or treated lumber are chosen for their aesthetic qualities and their wear resistance, and railings are generally made out of steel or aluminum.
Steel trusses are used too, but the material selected to make these components may be substituted in some cases. For instance, most steel options tend not to do very well in environments with high moisture and high incidences of salt exposure.
What Kinds of Pedestrian Footbridges Can Be Built?
Pedestrian walkway bridges come in all shapes and sizes, but almost all have truss, beam, or arch designs. In addition, there are suspension pedestrian bridges, but they are expensive to build and quite rare.
Truss Bridges
The superstructure on this type of bridge is a truss that is usually fabricated using triangular units. This construct provides a highly stable and efficient way to transfer the bridge’s loading requirements to its abutments.
The economic design considerations of the truss bridge’s depth will depend on factors such as chord stress levels, guardrail’s height, and shipping methods. Axcess can design and build trusses made out of either steel or fiberglass reinforced plastic (FRP).
Girder or Beam Bridges
Girder or beam bridges have a different aesthetic than other types because their primary supports are underneath the walkway and out of sight. They are not as efficient as truss bridges, but they cost less to build and install because fewer workers are needed.
Arch Bridges
Arch bridges are often the preferred choice because many people like them; however, they are not suitable for spanning long distances. Arch bridges are usually made out of curved steel or wood laminate beams. Arch bridges make a strong visual statement, but they are more expensive to build than truss or beam designs.
Taking the Guesswork Out of Pedestrian Bridges
If you need a pedestrian footbridge, you probably want the work to be completed on time and at a reasonable price. Axcess can meet these objectives with a business model that is collaborative, flexible, and authentic.
Instead of hiring a design company and then asking construction companies to bid on the job, Axcess can complete the entire project. We know how to build a footbridge from start to finish, and we specialize in footbridge design and construction. We understand all the critical steps of building a bridge and we also repair existing ones.
In addition, Axcess works closely with our clients to develop ideas that meet their needs and handle all aspects of the job, from preliminary engineering analysis to hiring a general contractor to final installation. We never consider a project complete unless the client is completely happy, and we always stand behind our work.
Contact Axcess Today for More Information
We hope you enjoyed our article on how long it takes to install a pedestrian bridge and found it helpful. Axcess can help you span the gap with a sturdy, long-lasting pedestrian bridge! If you would like to learn more about our services or are interested in seeing pedestrian bridges that we have built and installed, you can call us at (937) 907-0069, or contact us here!
