Turquoise Trail (NM14) Citizens Advisory Committee, c/o P.O. Box 245, Cerrillos, NM 87010
April 22, 2004
John McElroy, P.E.
NMDOT, District 5
P.O. Box 4127
Santa Fe, NM 87592
Re: NM14 lane width & Context Sensitive Solutions (CSS)
In answer to your question about why we have not been content with just striping 12 ft lanes at 11 feet along areas between Madrid and Cerrillos, we basically wish to retain as much of the intimate & traffic calming context of this part of the road as possible. Our answer then reflects both scenic and safety qualities.
We had long accepted expanding the physical width to 11 ft but were rather surprised that later in the design process 12 ft lanes were put back on the table. We have since felt convinced that the ominous sounding "off-tracking" rationale is effectively out-of-place and is not supportable by the accident history.
Our point is well argued in this resource about context sensitive solutions (CSS): "Report 480" "A Guide to Best Practices for Achieving Context Sensitive Solutions". You likely have it, but it can be obtained through the National Academy of Science at <http://www.national-acadamies.org> .
The document encourages design flexibility and has an interesting discussion of "substantive" vs. "nominal" safety, i.e. "substantive" (real problems) vs. "nominal" (existing in name only) safety. It openly encourages engineers to seek design exceptions when the situation warrants and to pause where well defined "performance based" problems do not exist.
We have seen no substantive evidence that "off-tracking" has been a problem along this stretch (Madrid to Cerrillos) even with the existing 10 ft lanes and very little shoulder.
An appropriate passage from the report:
"In the CSD/CSS environment, then, it would seem that the ability to incorporate and articulate safety in meaningful terms, both in problem definition as well as solutions, should be among the highest DOT management priorities.
"The ability to differentiate between substantive and nominal safety...is critical to successful development of acceptable solutions. Stakeholders no longer accept compliance with design standards as a safety rationale for accepting an adverse impact. DOTs must be able to demonstrate a substantive safety problem exists, and to do so in meaningful terms that can be directly related (by location as well as type) to the proposed solutions. Conversely, agencies should be assured that their limited dollars devoted to safety improvements will be well spent and return measurable benefits." [emphasis added]
We are pleased that the DOT has taken the Noland study (in Accident Analysis and Prevention, 2003) seriously by offering to consider striping at 11 feet. But insistence that there be 2 extra feet of pavement is seen by the CAC as an unnecessary "adverse impact" within the context of a design that could add to the roadside dimensions/disturbance, as well as actually blur the safety issues.
Instead, we see an opportunity to lessen disturbance by confining the physical width at 11 ft lanes to better, safely retain the context (feel) of this stretch of the road. These next 2 quotes also help remind us that we should be looking for such opportunities:
1) "THE SIZE AND MASS OF THE HIGHWAY AS IT PASSES THROUGH THE LANDSCAPE HAS A POWERFUL EFFECT ON THE TRAVELER'S AESTHETIC EXPERIENCE.... applied strictly by the book, such improvements [wider clear zones, lanes, and medians] can create a road that overwhelms the landscape" [emphasis added] --From: "Lessons from the Road, Case #2", National Scenic Byway Program.
2) "INTERNATIONAL SCANNING TOUR on Highway Geometric Design Summary Report" A report of the multi-nation European concept of the "self-explaining, self-enforcing road". Their engineers believe that narrow, winding, scenic roads have better multi-modal safety because of lower speeds. Excerpt: "A roadway design philosophy common in all [five] countries was the reliance on the physical roadway design to 'enforce' operating speeds and the development of a 'consistent' or 'self-explaining' look for each road category." --Posted on the Federal Highway Administration (FHWA) site.
The future potential of this area of the State, and the growing importance of the National Scenic Byway, has recently come more into focus as park development in the area continues.
Cc. Habib Abi-Khalil, Representative Rhonda King, NM 14 CAC
[To: NMDOT Response--May-13-04]
To: The CAC Turquoise Trail Page To Group's Actions To Resources for Saving America's Rural Roads and Communities--a listing. Page managed by RIII / CAC Page: April 2004 http://www.raintreecounty.com/Sav4-04.html