The advantages of prestressed concrete have been known for some time. But the technique of prestressing concrete for highway use has presented problems. And although many authorities believe that a prestressed concrete highway should have many advantages over a conventional road, the problem has been to find economical method of building it. Essentially, the Jones and Laughlin Steel Corporation's experiment consisted of anchoring connecting wire strands at opposite ends of a 400 foot section of roadway. The strands pass through flexible steel conduits which were imbedded in the concrete. When the concrete for the prestressed section was poured, a 6 foot gap was left in the middle of the section. For the prestressing operation, large hydraulic jacks were placed longitudinally in the gap. When the concrete had set, the gap was jacked apart to a width of eight feet, far enough to produce the required tension in the wire strands, and consequent compression in the concrete. When this was accomplished, the jacks were removed and concrete was poured into the gap.