We have teamed with Keller Engineers on several design-build projects for PennDOT. When selecting a designer, the more critical factors are trust and competence, more so than a low price. If your designer makes a mistake in quantities it can cost you a lot of money. We have stayed with Keller Engineers because we trust them to provide competent service at a competitive price. S. Scott Grannas, Vice President Grannas Bros. Stone & Asphalt Co., Inc.