PHYSICAL DESIGN CHALLENGES Corridor Cohesion Today’s corridors are physical legacies of trail and local street amalgamations based on a multiplicity of decisions, available funding, different engineering and design ideas and trends, configurations, si es, and scales. nless conceived for a single purpose, such as a ceremonial boulevard, corridors exhibit little physical cohesion. Their physical design is an inconsistent patchwork. Corridor land uses re ect local community oning, which is typically written to continue historic patterns and encourage investment. Conse uently, corridor municipalities economically compete with one another and are reluctant to share resources or development, inhibiting integrated corridor planning. Corridor uses have also evolved to re ect a corridor s purpose. or example, commuter corridors attract auto-oriented businesses, service stations, fast-serve restaurants, and retailers who favor those who drive. nd to complete the cycle, oning institutionali es this type of land use. hat has become lost is the appreciation that regional highway corridors are the front doors to most of the communities they serve. Community identity is eventually lost. Corridors take on a life of their own, separated from the communities they serve. Roadway Design Criteria n 6 the ederal ighway dministration published revisions to the 5 controlling criteria for design and how they are to be applied in different contexts on the National ighway System. ll ennD T highway roadways ualify. n roadways less than 5 mph, eight of the mandated design criteria for highway roadways were dropped however, all remain mandatory for speeds above 5 mph. andated Design Criteria for ighways with Speeds Below 5 mph Design speed Design loading structural capacity andated Design Criteria for Highways with Speeds 50 mph and Higher Design speed Design loading structural capacity Lane width Shoulder width Horizontal curve radius Superelevation rate Stopping sight distance aximum grade Cross slope Vertical clearance 3
Rotation of pavement on approach and through a hori ontal curve.
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