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# Clear Zone RDG Chapter 3. What is a Clear Zone? Clear Zone: A Clearer Definition A traversable area that starts at the edge of the traffic lane, includes.

## Presentation on theme: "Clear Zone RDG Chapter 3. What is a Clear Zone? Clear Zone: A Clearer Definition A traversable area that starts at the edge of the traffic lane, includes."— Presentation transcript:

Clear Zone RDG Chapter 3

What is a Clear Zone?

Clear Zone: A Clearer Definition A traversable area that starts at the edge of the traffic lane, includes the shoulder, and extends laterally a sufficient distance to allow a driver to stop or return to the road before encountering a hazard or overturning Clear Zone Traffic Lane Shoulder

Clear Zone Influence Factors Roadway Design Speed Traffic Volume Embankment slope Horizontal Curvature of the roadway

Minimum Clear Zone Distances

Slopes and the Clear Zone 1 4 3 1

Steepness Categories of Slopes Recoverable - 1:4 or Flatter ** Non-Recoverable: 1:3 to 1:4 ** Critical: Steeper than 1:3 **Traversable

Recoverable 1 4 (Traversable)

Non-Recoverable 1 4 3 1 ( Traversable )

Critical (Not Traversable) 3 1

Horizontal Curves and the Clear Zone

Table 3.2 Horizontal Curve Adjustments RadiusDesign Speed (mph) (ft)40455055606570 28601.1 1.2 1.3 22901.1 1.2 1.3 19101.11.2 1.3 1.4 16401.11.2 1.3 1.41.5 14301.2 1.3 1.4 XX 12701.2 1.3 1.41.5XX 11501.2 1.31.41.5XX 9501.21.31.41.5 XX 8201.3 1.41.5XX 7201.31.41.5XX 6401.31.41.5XX 5701.41.5XX 3801.5XX

Figure 3.6: VEE DITCHES Figure 3.6

Clear Zone Case Studies

Country road

Pavement markings

Add edge lines

Geometric and roadside inconsistency

Maintain Consistency In Roadway Design Don't Surprise The Driver!! Dont surprise the driver

Optimum design

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