Researchers demonstrated through lab testing that synthetic fibers in thin concrete overlays keep cracks tight and help transfer loads across slabs. Fibers with irregular cross sections and high lateral stiffness perform well in overlays. While increasing dosage levels up to 1 percent fiber volume fraction of concrete mixture improves load transfer across cracks and seams, using fiber dosage levels that exceed 1 percent fiber volume fraction renders mixtures largely unworkable. Researchers provide recommendations for selecting fiber types and dosages in pavement design, and suggest a test for trial batches.