For 3,000 years, people lived close to the land or in cities, their worlds limited to walking distance. Just 100 years ago, Henry Ford’s Model T changed all that, and America’s highways have strained to keep up ever since.

Our highways have vastly improved since the 1950s, when the Interstate system began, though conditions and congestion continue to be a challenge. Today’s 62,000 miles of interstates, freeways, toll roads and highways make up only 1.5% of our roads but carry almost one-third of our traffic, greatly expanding available choices of jobs, housing, shopping and recreation. Distant regional economies are now tied together. Roads are safer, too: Highway fatality rates today are one-fifth the rates of the 1950s.

In 2050, private vehicles will still provide the leading means of personal mobility. Vehicles will last longer and be cheaper relative to incomes. Improvements in conventional engines, along with alternatives such as fuel cells, electricity, natural gas and better batteries, will significantly increase average fuel efficiency and reduce emissions.

All of which means we will still have plenty of need for good roads.

Fast and not furious

In coming decades, most existing highways will be modernized, resurfaced or repaired. Innovative highway designs like diverging diamond interchanges, high-speed directional ramps, partial-access arterials and frontage roads will increase traffic capacity and safety. Pop-in uniform bridge designs and task-force construction contracting will allow for rapid replacement.