FLH PDDM Chapter 9 - Eastern Federal Lands Highway Division

9.4.A. Geometric Design. (continued)Consider widening to provide additional clear distance through short sections of rock cuts. In longer rock cuts,protrusions are cut back or protected where warranted. A review of accident data will help to define dangerousobstructions. Good engineering judgment, cost effectiveness, and consideration of environmental andcommunity impacts may also influence decisions.Under urban conditions, the minimum setback for obstructions should be outside the paved shoulder or600 millimeters behind the curb. Where there will be sidewalks, it is desirable to locate the obstructionsbehind the sidewalk.Safety items reduce the severity of run-off-the-road accidents. These items include traffic barriers (includingbridge rails), flattening slopes to eliminate the need for barriers, crash cushions, breakaway or yielding signsupports, and breakaway luminaire supports.Refer to section 10.3.F in Chapter 10 for a discussion on bridges on RRR projects.All RRR projects should consider the following safety enhancements:Upgrading all rail and end treatments to current standards. Evaluate existing traffic barrier rail, bridge rail,guardrail, and end treatments for need and compliance with standards.Extending cross pipes outside of the clear zone if practical, orInstalling beveled pipe ends or end sections for both parallel and cross-drain structures located in the clearzone.Relocating, protecting, or providing breakaway features for sign supports and luminaries.Protecting exposed bridge piers and abutments.Modifying raised drop inlets that present a hazard in the clear zone.Sign and mark all RRR projects according to the MUTCD.9 - 57