ACTS

Roadway Friendliness Tool

Treatment 14: 25-30 Foot Curb Radius

National guidance: The AASHTO Geometric Design of Highways and Streets, 1994 Edition, provides a wide range of acceptable curb radii, from 10-to-60', depending on the intent of the highway jurisdiction.

Where might you find this on your system: You might find this treatment at intersections.

Recommendation: Due to reduced physical strength, older drivers may have difficulty executing tight turns, which can result in their vehicles swinging into the opposing cross-street lane during the turn. This is more likely to be a problem turning off a major road (car decelerating from speed) as opposed to turning onto a major road (turn begun from stopped position). Providing a modest increase in turn radii, up to 25' or 30' on specific corners, can address this problem.

Conflicts with other community goals: Larger curb radii permit or encourage higher turning speeds from the general driving public. That improves traffic flow, and is usually considered desirable along major routes; but its often considered undesirable within neighborhoods. Similarly, larger turn radii produce longer crosswalk dimensions, which increases pedestrian exposure during crossings.

Ease of implementation: Widening of curb radii requires relocation of the sidewalks at the corner, and regrading of the nearby surface - and may require purchase of permanent or temporary right-of-way to allow this work. Curb widening could involve relocating underground drainage pipes, catch basins, or utility lines and may involve relocating above-ground items such as telephone poles, signal poles or street lights. Coordination with utility companies may be required. A two-person crew or larger, with front-end loader and cherry picker, is needed depending on specific work items. Utility companies will do their own work.

Previous Treatment | Next Treatment
Roadway Friendliness Tool