NM 532 Curve Correction Project - New Mexico Department of ...

NM 532 Curve Correction Project Environmental Assessment
1.0 SUMMARY
The New Mexico Department of Transportation (NMDOT), in cooperation with the Federal Highway
Administration (FHWA), proposes to reconstruct three curves of the NM 532 roadway in Lincoln County,
New Mexico (see Figure 1.1). NM 532 is a rural arterial roadway that extends from NM 48 in Alto to
Ski Apache, and it provides the only roadway access to Ski Apache and nearby areas on the Lincoln
National Forest. The project area is located within NMDOT District 2. The NM 532 Curve Correction
Project is listed in the Fiscal Year (FY) 2012-2015 Statewide Transportation Improvement Program
(STIP) Amendment 4 as control number (CN) 2101140. The NM 532 Curve Correction Project EA was
developed in accordance with the National Environmental Policy Act (NEPA), NMDOT Location Study
Procedures (NMDOT, 2000) and Federal Highway Administration (FHWA) Technical Advisory T
6640.8A, 23 Code of Federal Regulations (CFR) Parts 771 and 772, and other applicable guidelines and
regulations.
The purpose of the NM 532 Curve Correction Project is to improve traffic and safety conditions between
MP 0.0 and MP 12.0 while considering the needs of local residents, forest visitors, and the Mescalero
Apache Tribe. The project need is based on the following conditions: insufficient shoulder width;
roadway geometry does not meet current standards resulting in several sharp curves; post-fire soil erosion
undercuts the roadway, steep drop-offs next to driving lanes; limited signage to inform drivers of roadway
conditions; lack of pull-off areas; poor pedestrian access at scenic areas; extensive maintenance needs;
and economic viability of recreation-related businesses.
The following three curves are proposed for extensive reconstruction: Texas Turn at MP 6.89-7.05, Axle
Bend Curve at MP 8.21-8.37, and Last Curve at MP 11.86-11.95 (see Figure 1.2). These curves have
been identified as priority for improvements. Work would entail increasing the curve radii and correcting
the curve grades. At each curve, a retained soil system (RSS) wall would be constructed using additional
native fill. The RSS would consist of a geo-grid embankment constructed at a 0.5:1 slope with rock-filled
baskets for the wall face. Perforated drainpipes and subsurface drain outlets would be installed as part of
the RSS wall. Guardrail would be installed at the top of the embankment. Energy dissipaters or other
similar slope protection measures would be installed in areas where drainage has caused severe erosion.
On the upslope side of Axle Bend Curve, some rock would be excavated and removed. No blasting
would occur. Rock or slope protection would be used to create a stabilized rock-cut face only if unstable
rock is encountered.
The current proposed typical section would consist of two 11-foot travel lanes, two 3-foot shoulders, and
two 2.5 foot tapers. Existing vehicle pull-off areas at each curve would be paved. In some areas, slopes
would be excavated and additional fill would be placed. Walls, guardrails, and signs would be installed in
some sections.
The total estimated project cost for the Recommended Build Alternative is $1.8 million. Construction of
the project would begin in 2013.
This EA concludes that the Recommended Build Alternative meets the purpose and need of the proposed
project and is not expected to have significant adverse social, economic, or environmental impacts that
will warrant an Environmental Impact Statement. Unless significant impacts are identified as a result of
public review, a Finding of No Significant Impact (FONSI) will be requested from FHWA. If a FONSI is
issued, it will provide approval for final design and construction of NM 532 at Texas Turn at MP 6.89-
7.05, Axle Bend Curve at MP 8.21-8.37, and Last Curve at MP 11.86-11.95.
March 2013 1 CN 2101140