13. Roadside & Cross Section Design Flashcards
What slopes are consider recoverable?
1V:4H or flatter
What slopes are consider non-recoverable?
Between 1V:3H and 1V:4H
What slopes are consider critical?
Steeper than 1V:3H
Where on a horizontal curve are cars more likely to leave the road?
Outside of the curve (tangent of the curve)
What is the ADA requirements for ramp/sidewalk cross slope?
1% (min), 2% (max)
What is the maximum ADA longitudinal slope of a ramp?
8.33% (1V:12H)
What is the maximum ramp run rise per ADA?
30 in
What is the recommend clear zone for AASHTO “Green Book”?
7 to 10 ft
What is the order of priority for mitigating roadside hazard’s?
Removal, relocation, reduction of impact severity, sheilding with traffic barrier.
When would the non-transverseable clear zone be considered transverseable?
If it’s free of fixed objects
Where does the clear zone begin?
At the edge of the traveled way or oriented from the outside or inside shoulder (in median applications).
What is the design clear zone a function of?
Design speed, side slope, and traffic volume
Per the Green Book what is the minimum lateral offset from a curved road? At the intersection?
1.5 ft, 3 ft
What are the two Test Levels (TL) or barriers?
TL2 for speeds less than or equal to 45 mph (local roads); TL3 for speeds greater than 45 mph (freeways/expressways)
For roadways with no curb and gutter the minimum with of a bike lane is?
4 ft
What is the recommended width of a bike lane from the face of the curb or guardrail to the bike lane stripe?
5 ft
How should bike lanes be delineated from travel lanes?
6 in soild white line
What techniques can be used for traffic calming?
Speed humps, traffic circles, median islands, chokers, bulb out at intersections, lateral shifts, raised intersections
What are the two testing standards for barriers?
NCHRP 350 and Manual for Assessing Safety Hardware (MASH)
What are the three types of barriers systems?
Flexible, Semi-Rigid, and Rigid
What is considered part of the Clear Zone?
Shoulders, bike lanes, and auxiliary lanes (not functioning like through lanes)
What are guardrail warrants based on?
embankment height and slope
