Sunday, November 16, 2014

Shoddy Signs Spotlight: Introduction

The "Shoddy Signs Spotlight" is a new piece that will be a staple of State and Local Road Reform where a lazy, incorrect, worn out and/or ineffective application of traffic signs in known or random locations is selected and discussed here.  In these locations the location on street view will be shown if possible.  Aerial photography of the selected location will always be used in the posts as well if there is an improvement that could be made beyond a simple sign replacement with the potential replacement shown.  Nothing in these "Deficient Safety Standards Spotlight" pieces should be constituted as an official engineering study nor treated as such.  This is simply meant to highlight failures of engineering practice on a state or local level that make driving far more hazardous than it should be.  Since fixing traffic safety policy is a major priority of the State and Local Road Reform, it is important to educate the public on where problems are found, what is the problem and why they should be fixed.  In all "Spotlight" posts, engineering errors are shown that often aren't fixed, should be there but are not there, are done the wrong way deliberately.  The detail in these posts are because these conditions are typically not understood readily by the public.


For this week, I am going to introduce a reverse turn on a road in Bartow County, GA signed incorrectly.  Named Rock Ridge Road, this local roadway is incorrectly posted with right curve signs when the condition warrants far better signage.  Bartow County has a traffic engineer (although no PTOE is hired), and the county has a population of over 100,000 residents so the situation cannot be based on lack of means or personnel although it is reasonable assumed the county engineer has little or no direct involvement with traffic sign installation or maintenance.

What is shown here is the use of a curve sign in a reverse turn with no advisory speed or arrow signs in the sharpest turn.  Likely the county thought it was cheaper just to use their most available curve signs with no actual engineering study ever done on this curve to determine how it should be posted.  Since the speed limit is 30 on this road, an advisory speed is required if the curve is determined via a proper ball bank or accelerometer study to be 10 MPH below the posted speed, which is likely the case here [MUTCD, Section 2C-08 and Table 2C-5].  Also, a switch to a W1-3R (Right Reverse Turn) sign vs. a W1-2R (Right Curve Sign) sign is needed since the speed in the turn is definitely less than 30 MPH.  The turn also appears suddenly especially northbound and is a 90 degree turn so W1-6 arrows are certainly recommended in both directions and required if the curve advisory speed is determined to be below 20 MPH.

Here are some photos below of the field conditions as of October 2014:

Southbound curve sign.  This does not indicate the sharper turn less than 250' away.  No other sign is used, and in these cases a Reverse Curve (W1-4) or Reverse Turn (W1-3) should be used if two curves or turns are less than 600' from each other [see MUTCD, Section 2C.07].  

Northbound curve sign.  Note that the curve is not readily visible, and no indication is needed that traffic should slow down for the 90 degree turn just out of view.

The location is shown below on street view from 2008:

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