Building confidence in design-build

As more counties and municipalities explore alternative project delivery methods, many are finding themselves in unfamiliar territory. Design-build has been a common delivery method for state departments of transportation for years, but it could be a beneficial method for local agencies, too, even if those often have less experience with the approach and may be evaluating its benefits and risks for the first time.

I've found that successful design-build projects aren't necessarily defined by their complexity. They're defined by how early teams identify challenges, how effectively they communicate, and how well they manage risk before construction begins.

That's why projects like Gwinnett County's Ingram Road Bridge Replacement are so important. As only the third design-build project undertaken by the Gwinnett County Department of Transportation, it provided an opportunity to demonstrate how the right team, the right process, and the right expertise can help local agencies successfully navigate alternative delivery. 

The foundation of design-build success

At its core, design-build is about collaboration. The compressed schedule and overlap between design and construction create opportunities to accelerate delivery, but only if everyone is aligned early.

In my experience, successful design-build projects require several key elements:

• Thorough review of preliminary costing plans
• Early identification and resolution of potential risks
• A clearly defined basis of design
• Development of a detailed design schedule upfront
• Careful management of right-of-way constraints
• Early and persistent utility coordination
• Frequent communication among all stakeholders
• Regular field visits

Many of these activities are standard contractual requirements. The difference is how early they happen. When utility coordination begins early, when design assumptions are documented upfront, and when stakeholders are communicating consistently, everyone is working from the same understanding of the project.

That alignment creates a strong foundation for the entire project team. 

Why field visits matter

The Ingram Road Bridge Replacement project, involves replacing a functionally obsolete bridge over Bromolow Creek Tributary within the existing right of way. The project is being delivered on an accelerated schedule, with design and construction documents completed in approximately six months and a total contract duration of one year.

One reason the project got off to a strong start was the quality of the costing plans included in the procurement package. The design consultant who developed the preliminary costing plans did a thorough job defining the project scope, completing a preliminary hydraulic analyses, and providing information that helped reduce uncertainty for both the contractor and design team.

Having that information available lowered risk and helped us develop a competitive proposal because the scope was well defined from the beginning.

But even the best preliminary plans can't replace getting boots on the ground.

During field visits, we observed evidence of existing scour and creek migration that raised concerns about the preliminary bridge layout. On paper, everything appeared reasonable. In the field, however, we recognized that the proposed configuration could leave the bridge vulnerable to future scour issues as the creek continued to migrate over time.

Because we identified the concern early, we were able to adjust the bridge layout and improve the design without expanding the project scope.

Rather than extending the bridge — which would have increased costs and potentially required additional funding — we shifted the bridge location, incorporated bank armoring, and keyed riprap into the channel bank to help protect against future scour. The solution improved long-term performance while remaining within the original scope and budget.

That's exactly why field visits remain critical. Sometimes you don't identify the most important project risks until you're standing on site and looking at conditions firsthand. 

Staying within scope through early problem solving

Another benefit of early coordination became apparent during our review of the project's drainage system.

The preliminary concept tied into an existing drainage system in a way that would have required relocating a utility pole. Utility relocations can introduce additional costs, schedule impacts, and coordination challenges, particularly on accelerated projects.

Working closely with our drainage and roadway teams, we redesigned the system so that we could improve the outfall location and eliminate the need for the utility relocation altogether.

The revised design remained within the existing right of way and removed a potential source of risk before it became a construction issue.

Those types of solutions don't happen by accident. They come from bringing the right people together early and maintaining open communication throughout the project. 

Why design-build works well for local agencies

I believe design-build can be particularly effective for local governments, especially for bridge replacements and transportation projects that can remain within existing right of way.

These projects tend to have fewer unknowns and allow owners to realize the schedule and collaboration benefits that design-build offers without taking on excessive risk.

As projects become more complex — with significant right-of-way acquisition, complicated staging requirements, challenging hydraulics, or complex roadway geometry — the risk profile changes. Those projects can still be good candidates for design-build, but they require even greater coordination and risk management.

For relatively straightforward bridge replacements like Ingram Road, design-build allows owners to move faster while maintaining collaboration between designers, contractors, and stakeholders throughout the process.

The key is having access to experienced teams that understand how to manage the unique challenges that come with alternative delivery.

Bringing national experience to local clients

One advantage Garver brings to local agencies is access to a nationwide transportation network with extensive design-build experience.

Many municipalities and counties are encountering design-build challenges for the first time. Meanwhile, transportation agencies across the country have already delivered hundreds of projects using design-build and progressive design-build approaches.

We regularly tap into expertise from across Garver's transportation practice to share lessons learned, best practices, and delivery strategies from projects nationwide. That allows local clients to benefit from experience gained in other states and markets without having to learn every lesson through trial and error.

For clients new to design-build, that knowledge transfer can be just as valuable as the engineering itself. 

Looking ahead: the next evolution of alternative delivery

The Ingram Road project demonstrates the value of collaboration, early coordination, and proactive risk management in a design-build environment. But it's also an example of how owners can continue evolving their approach to project delivery.

While Ingram Road was delivered as a design-build project, aspects of the contract structure reflected principles commonly associated with progressive design-build, including phased design milestones and close collaboration before construction.

Progressive design-build takes this concept a step further. Owners, designers, and contractors work together during project development to refine scope, validate costs, and reduce uncertainty before establishing a final construction price.

We've already begun helping local agencies explore that next step. In Forsyth County, Georgia, Garver is currently supporting the state's first progressive design-build transportation project: a bundle of intersection improvement projects that includes pedestrian infrastructure and new roadway construction.

For local governments considering alternative delivery methods, progressive design-build offers another opportunity to reduce risk, improve collaboration, and create greater flexibility throughout project development.

As more counties and municipalities embrace design-build, the most successful projects will be those that combine local understanding with proven experience. By leveraging expertise from transportation professionals across the country, we can help local agencies confidently adopt these delivery methods and achieve better outcomes for their communities.