Hydraulics.pdf

April 18, 2016 Mr. Tom Puto Federal Highway Administration Central Federal Lands Highway Division 12300 West Dakota Avenue, Suite 380 Lakewood, CO 80228

Re: NM FLAP 77000(1) Buckman Road Segment of the El Camino Real De Tierra Adentro National Historic Trail Accessibility of the Existing Shared Use Path Undercrossing of NM 599

Tom:

BACKGROUND

Loris and Associates has been contracted by HDR, Inc. to assist in the engineering design of the subject project. This project consists of an approximately 15 miles of shared use path and recreational trail which approximately retraces the El Camino Real De Tierra Adentro National Historic Trail. The southern 2.5 miles of this project will be a 10 foot wide paved shared use path. The shared use path segment of the project will provide a connection to the existing Santa River Trail (a paved shared use path following the Santa Fe) and the Municipal Recreation Complex and continue on north to County Road 62 in the Caja Del Rio Road right of way.

The purpose of this memo is to discuss accessibility concerns at the existing equestrian crossing structure beneath NM 599.

EXISTING CONDITIONS

The southern portion of the shared use path will traverse property owned by the State of New Mexico and NMDOT. It is intended that the path be located within an existing average 48 foot width trail easement across the State of New Mexico property and utilize an existing equestrian crossing beneath NM 599 and the NM 599 frontage road.

The existing undercrossing consists of a 14 foot wide by 10 high by 230 foot long concrete box culvert with 100 foot long open rectangular boxes used for the structure approaches at each end.

According to the “As Built Plans” provided by NMDOT (see Exhibit A), the profile of the crossing approaches were designed to provide 30 foot long segments at 8.33% grade (1:12) separated by 5 foot long flat landings. This was designed to meet the Americans with Disabilities Act (ADA 2010) Standards for Accessible Design for Buildings. However, based on topographic survey provided by Woolpert in October, 2015, the actual grades of the existing structure appear to be as follows:

• South Approach: 100’ at 7.0% with no landings.

• North Approach: 55’ at 9.3%, 10’ at 4.7%, 35; at 6.3%.

Additional Site Details include:

• The existing length of path that exceeds 5% grade is only a total of 200 feet in length of the total proposed paved shared use path length of 3.35 miles. This is only 1.1% of the total path length.

Accessibility of the Existing Shared Use Path Undercrossing of NM 599

• The closest accessible access point to the underpass location is 1 mile to the south and a

1.25 mile to the north. The underpass is not located between these access points and any finite destinations.

• The existing facility meets other accessibility requirements (2% maximum cross slope , continuous width greater than 5’, smooth, firm and stable surface).

CURRENT ACCESSIBILITY GUIDELINES

The only fully adopted and enforceable accessibility standards are the 2010 ADA Standards for Accessible Design. However these were established to specifically address accessibility of buildings and access to buildings. The US Access Board fully acknowledges that the 2010 ADA Standards are not applicable to pedestrian facilities in public rights-of-way or on shared use paths.

In February 13, 2013 the US Access Board issued a Supplemental Notice of Proposed Rulemaking to establish Accessibility Guidelines for Pedestrian Facilities in the Public Right-of- Way; Shared Use Paths (see web link below). As of February, 2016, these guidelines are still proposed but are expected to be fully adopted and published in 2017. Considering that there are currently no fully adopted accessibility guidelines that apply to shared use paths, the Access Board recommends use of the best available design guidelines, which are included in this proposed rulemaking.

https://www.access-board.gov/guidelines-and-standards/streets-sidewalks/shared-use-paths/background/supplemental-notice

Excerpt from the United States Access Board Rulemaking on Shared Use Paths

R302.5.1 Within Street or Highway Right-of-Way. Except as provided in R302.5.3, where pedestrian access routes are contained within a street or highway right-of-way, the grade of pedestrian access routes shall not exceed the general grade established for the adjacent street or highway.

R302.5.2 Not Within Street or Highway Right-of-Way. Where pedestrian access routes are not contained within a street or highway right-of-way, the grade of pedestrian access routes shall be 5 percent maximum.

R302.5.3 Within Pedestrian Street Crossings. Where pedestrian access routes are contained within a pedestrian street crossing, the grade of pedestrian access routes shall be 5 percent maximum.

R302.5.4 Physical Constraints. Where compliance with R302.5.1 or R302.5.2 is not practicable due to existing terrain or infrastructure, right-of-way availability, a notable natural feature, or similar existing physical constraints, compliance is required to the extent practicable.

R302.5.5 Regulatory Constraints. Where compliance with R302.5.1 or R302.5.2 is precluded by federal, state, or local laws the purpose of which is to preserve threatened or endangered species;

the environment; or archaeological, cultural, historical, or significant natural features, compliance is required to the extent practicable.

https://www.access-board.gov/guidelines-and-standards/streets-sidewalks/shared-use-paths/background/supplemental-notice https://www.access-board.gov/guidelines-and-standards/streets-sidewalks/shared-use-paths/background/supplemental-notice

CONCLUSION

The grades of the approaches of the existing undercrossing as described above exceed 5% grade (R302.5.2). Modification of the existing structure to provide 5% maximum grades would require complete removal and reconstruction of both approach structures. Since the approaches consist of a monolithic open box structures, where the bottom slab of the box functions as the path surface, there is no way to reduce the path profile to provide 5% grade without also removing and replacing the walls of the box. Provision of 5% maximum grade will require the 5% grade to extend approximately 600 linear feet to the north. The estimated cost of reconstruction of the approaches is greater than $400k (See Exhibit D).

In addition the high cost of full replacement of the approach structures, the following physical constraints exist:

• The excavation and construction operations expected to remove the existing approach structures and reconstruct the new structure is likely to require additional area outside of the existing trail easement. An additional grading and construction easement would be required.

• A deep excavation (approximately 14 feet deep) would be required directly adjacent to the shoulders of NM 599. This would require shoring to protect the existing shoulders and travel lanes of NM 599 and would require temporary traffic control on NM 599 during construction.

• Reduction of the structure approach grade to 5% would require that the trail be lower in in the area adjacent to the structure. This would require a 5% continuous grade for 570 linear feet. This entire section would be lower than the adjacent grade. As a result, stormwater would be directed into the underpass for this entire length. Due to this lower trail grade, there is no practical way to redirect water away from the structure.

Based on the relatively high cost of replacing the existing approach structures and the physical constraints mentioned above, and considering the additional site details listed above, Central Federal Lands Highways Division (CFL) and Santa Fe County may wish to consider compliance to be “impractical” and leave the existing structure in place according to R302.5.4 of the proposed guidelines. However, if the cost of the reconstruction of the approach structures IS considered practical, the design and construction of new approach structures must be included in the project.

CFL and/or Santa Fe County may wish to discuss this matter directly with the U.S. Access Board.

US Access Board Technical Assistance can be contacted at:

(800) 993-2822 row@access-board.gov mailto:row@access-board.gov

Please advise us of if we should proceed with the existing approach structures in place, or full removal. If you would like to discuss this further, please do not hesitate to contact me.

Respectfully submitted, The Office of Loris and Associates, Inc.

Scott Belonger, P.E.

Project Manager

Exhibits:

A – As-Built Drawings of Existing Undercrossing Approach Structures B - Undercrossing Plan and Profile with Existing Approach Remaining In-Place C - Undercrossing Plan and Profile with Existing Approach Structures Removed and Replaced

D - Cost Estimate for Removal and Replacement of Approach Structures