Quiz #28

[John QPE]

When designing a shifting taper for a temporary traffic control zone on a roadway with a posted speed limit of 55 mph, the taper length should be at least:

A. 0.25L

B. 2L

C. (WS)/2

D. (WS^2)/60

 

[geomane]

I got "C"

 

[Dexman PE PMP]

MUTCD Section 6C.08 

http://mutcd.fhwa.dot.gov/htm/2009/part6/part6c.htm

Shifting taper is L/2 where L = WS for speeds over 45mph

Answer = C

To further expand on that, W is the width of the lane and S is the posted speed.  If space is limited, you can reduce the speed to shorten the taper length.