A variety of components can accommodate various load-carrying capabilities and span potentials. Connections between elements are simple -- carefully planned details result in economy. Well-developed and time-tested standards Since the first introduction of prestressed concrete in the United States, the design standards for bridge structures have continually evolved and are today governed by national AASHTO standards, as well as design, manufacturing and quality assurance standards of the Commonwealth of Pennsylvania and other States. Adaptable to a wide variety of situations Precast prestressed concrete products can be designed and manufactured for any application, ranging in size from short span bridges to some of the largest projects in the world. When using prestressed concrete beams for replacement of existing bridges, the existing abutments and piers frequently can be used. Attractive and aesthetic fit Because of the simple, clean shapes of the member used, prestressed concrete bridges offer attractive views from all sides.Strong, tough, durable -- yet graceful bridges result from the low depth to span ratios which are possible through the use of prestressed concrete.