State Highway Access Manual - Sight Distance Standards

Appendix G: Highway Design Reference

Notes:

1. Values and methodology based on A Policy on Geometric Design of Highways and Streets, AASHTO, 2001 for the design speeds shown. Intersection sight distance values shown are governed by the left turn movement from the access point onto the state highway (Case B1, p.660).
2. Assumes passenger vehicle for design purposes and level grade +3% maximum.
3. Refer to the AASHTO guidelines to address different conditions (e.g. access limited to specific turning movements, more than two opposing lanes of traffic to be crossed, steep grade, median crossover, other design vehicles, etc.).
4. Sight distance measurement must conform to the AASHTO models.
5. Refer to 10.4 for discussion of sigh distance requirements and any substandard conditions