Category:143 Practical Design

Funding for highways is rarely adequate to cover all the needs of the system, and a recessed or depressed economy only complicates the issue. In 2004, MoDOT recognized such an economy on the horizon. Realizing it had no control over its future funding stream, the department began to focus on the most efficient way to spend its money, however small the amount.

This change in philosophy marked the birth of the Practical Design concept. Under the Practical Design model, a project is structured solely on the basis of its purposes and need, no more, and no less.

For example, if a bridge over a creek can no longer convey traffic safely, the purpose and need is to provide for that crossing. In the past, however, design standards would dictate that the new structure be wider, higher and longer than the existing. There was also a tendency to upgrade other highway aspects in the general vicinity just because they were there.

Practical Design pointed out that, in many cases, the existing bridge had functioned flawlessly for decades. As such, it suddenly began to seem ridiculous to needlessly inflate the new structure when its only deficiency was its poor structural condition.

Practical Design defines the scope by focusing on achieving the project purpose and need while considering the surroundings of each project. It encourages sensitivity to where the project is located, whether it is an interstate or a letter route and allows the surrounding context to help determine the design criteria. Practical Design's goal is to produce the best value for the least cost. Life cycle costs must be considered so the burden is not shifted to maintenance.

MoDOT identified the small percentage of its standards that accounted for the vast majority of its expenditures. Those standards were studied and rewritten with greater flexibility, allowing for more innovation on the part of designers. Even with the greater flexibility, standards in the practical design system function as a starting point for project decisions, rather than a destination. The real project decisions are based entirely on the purpose and need of the facility as well as its context.

Practical Design provides good solutions across the entire system, as opposed to perfect solutions in isolated locations. In this manner, the entire highway system improves and even a modest budget can be stretched to provide quality transportation for Missouri’s taxpayers.