The business of beautiful bridges

Far more than simply tools for moving from point A to point B, many bridges become popular symbols of their cities. All bridges are not created equal, however; no one would confuse a generic river crossing with a Golden Gate.

As the public becomes more sophisticated about design in general, aesthetics are an increasingly important part of the conversation whenever new bridges are proposed. At the same time, however, the growing prominence of public-private partnerships is making it more difficult to build beautiful bridges.

PPP problems

Until relatively recently, governments typically commissioned bridges by first hiring a designer to produce the plans and specifications, then contracting with a construction company to build the project.

Today, however, the desire to cut construction costs and schedules, leverage private finance, and minimize public risk has made public-private partnerships (PPPs) and design-build arrangements almost ubiquitous in North America. These models can vary widely: although the scopes of work include at least both design and construction, the group selected for the project may also be tasked with financing, maintenance, revenue collection, and more.

The growing prominence of public-private partnerships is making it more difficult to build beautiful bridges

Historically, the group controlling the bridge’s design (i.e., the government) was the same group that ultimately owned and was held politically accountable for it. With PPPs and design-build projects, however, this is not the case — one factor that has led visual concerns to be neglected.

The Golden Gate Bridge has a fascinating procurement history of its own; it was financed by a $35 million bond issue during the middle of the Great Depression

Finances also play a role. Although high-quality aesthetics don’t have to raise the price tag dramatically, they do carry some additional costs. In a PPP arrangement, the team hired to build the bridge has a strong incentive to keep costs as low as possible — the greater the difference between the bridge’s price tag and the revenue it ultimately generates, the greater the team’s profit.

Public perception

This dynamic has not gone unnoticed by the public. In Montreal, for example, there has been a heated (and sophisticated) conversation around the New Bridge for the St. Lawrence Corridor. As the Globe and Mail wrote, “Montreal doesn’t get to build a bridge very often, and for a city that is attempting to rebrand itself as a creative metropolis, building an architectural landmark as inspiring as France’s Millau Viaduct is not an occasion to be missed.”

Despite the high hopes, however, scepticism reigned. Even after the owner appointed a renowned international bridge architect (along with Arup as engineer and technical advisor), the general sentiment during the project’s early days was that aesthetic concerns would get squeezed out. Thankfully, the recently released renderings of the final design have been well received.

Rendering of proposed New Bridge for the St. Lawrence Corridor

Economy sedan vs. high-end convertible

To understand the dilemma clients and contractors face, it’s helpful to consider a consumer product parallel. By law, every car that manufacturers sell has to meet minimum standards for safety and performance. However, neither legal requirements nor commercial incentives mandate that every car be a work of art. Knowing that most of us can’t afford Lamborghinis, car companies offer no-frills economy sedans as well as high-end showpieces. Buyers select which of the many options available best meet their needs for both amenity and affordability.

Describing aesthetic requirements in a manner that contractors can actually use is extremely difficult

Today’s bridge business works in a similar fashion. Designers and contractors are obligated by law and industry norms to make sure that every bridge complies with baseline requirements for safety and functionality. On the subject of aesthetics, however, laws and industry norms are silent; a project team’s only obligation in this realm is to meet its client’s expectations. And, as it turns out, describing aesthetic requirements in a manner that contractors can actually use is extremely difficult.

The Brooklyn Bridge, a marvel of engineering and aesthetics when it opened in 1883

Raising the bar

Although several different means of addressing this problem have been developed, we feel that one is clearly superior.

The most effective means of shepherding high-quality design throughout every stage of the project is a two-stage process of creating what are known as reference and definition designs. These clarify the owner’s intentions in terms of aesthetics, ensure that technical and visual dimensions of the design are considered simultaneously, and provide a plan for safeguarding architectural integrity through the final stages of the project.

Reference and definition designs serve two separate but complementary functions, and both should be included in the RFPs issued to the interested firms. The reference design’s purpose is to help the owner and its consultant team understand the project’s technical requirements and prepare cost and schedule estimates. It’s generally prepared in parallel with the development of the technical requirements and tender documents.

Although it is reasonably common to prepare a reference design, clients don’t typically focus much energy on it, as they know that the final design will almost certainly be very different. For the process we propose, however, it needs to be highly fleshed out, encompassing an architectural review that determines a preferred form.

The client’s team then uses the reference design to prepare a definition design, which includes a set of drawings showing the must-haves for configuration, geometry, and form for the final bridge.

The first use of a definition design occurred in the ’90s with the Øresund Link, which connects Denmark and Sweden. Although the architectural form had been selected through a design competition, the team realized that it would be impossible to describe in words which elements of the winning design were mandatory and which could be changed to suit the design-build team’s needs. It therefore developed a set of drawings showing must-keeps such as the geometry of the main structural elements.

The result: a bridge that was completed on time, within budget, and without claims, and has won wide acclaim for its aesthetic appeal.

Renderings prepared by the owner’s consultant team before the procurement demonstrate that the finished bridge (below) reflects the design intent

Having been involved with various kinds of bridge procurement processes around the world, we believe that this method results in the most satisfactory outcome for all parties.

Rendering of Queensferry Crossing, now in construction in Scotland. The bridge was procured through a design-build contract with a definition design

Although some argue that the definition design approach limits private-sector innovation, we haven’t found this to be the case. Instead, it pushes design-build teams to develop holistic solutions that address form, function, and business — rather than, as is all too common, focusing primarily on issues of cost and supply chain.

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