Scenic Byways

Thirty-six state and two federal agencies have recognized 34,000 miles of roads as scenic byways--roadways that provide access to historic, cultural, recreational, and other resources. Many of these roads were built years ago, often to specifications that fall short of today's geometric design standards governing the physical layout of roads. In relying on current standards to improve or reconstruct their scenic byways, state highway agencies could end up damaging the byway's scenic character because the standards emphasize mobility and safety rather than preservation. To help prevent such damage, Congress passed legislation giving state highway agencies the flexibility to apply alternative to the geometric design standards for improving and reconstructing scenic byways. This report discusses (1) what design standards states use or plan to use to improve and reconstruct roads in scenic areas and (2) what national design standards or guidance is available to state for improving and rebuilding such roads. In addition, GAO provides information on design approaches to reconstructing one scenic byway--Rhode Island's Ministerial Road--to illustrate the trade-offs involved in different design standards.

GAO found that: (1) twenty-four of the 29 states surveyed use the American Association of State Highway and Transportation Officials' guidance (green book) as their standard for improving or reconstructing their scenic byways; (2) the green book affords enough flexibility to preserve scenic resources while meeting the states' needs for mobility; (3) states rely on the green book because they are concerned that they may be sued for a deficient design if an accident occurs on a road that has been designed using an alternative design standard; (4) the remaining five states have developed or are planning to develop their own standards to avoid having to take design exceptions; (5) there are other sources available to states concerning the national guidance standards on geometric design, including the National Park Service's (NPS) Park Road Standards and the Transportation Research Board's (TRB) criteria for resurfacing, restoring, and rehabilitating roadways, which is referred to as the 3R criteria; (6) NPS standards give higher priority to scenic preservation, while the 3R criteria emphasize preserving the existing roadway; and (7) the issues in selecting the appropriate design standard for a scenic byway depends on the primary purpose of the road.