New Mexico Administrative Code › Title 17 - PUBLIC UTILITIES AND UTILITY SERVICES › Chapter 4 - UTILITY RIGHTS OF WAY AND EASEMENTS › Part 2 - REQUIREMENTS FOR OCCUPANCY OF STATE HIGHWAY SYSTEM RIGHT-OF-WAY BY UTILITY FACILITIES › Section 17.4.2.15 - INSTALLATIONS ON HIGHWAY STRUCTURES

Current through Register Vol. 35, No. 13, July 16, 2024
Attachment of utility lines to a highway structure can
				  materially affect the capacity of the structure, the safe operation of traffic,
				  the efficiency of maintenance and reducing the aesthetic appeal of the
				  structure.
A. Where it is feasible to
				locate utility lines elsewhere, attachments to highway structures should be
				avoided. However, when installation of the utility at an alternate location
				proves to be extremely difficult or unreasonably costly, consideration will be
				given for an attachment of utility lines to a highway structure. The attachment
				shall be made by a method acceptable to the Bridge Engineer of this
				Department.
B. All proposed
				attachment methods shall conform to adequate engineering considerations for
				preserving the highway structure's integrity, safety, ease of maintenance, and
				its appearance. In this respect, the following considerations shall
				govern:
C. Due to variations in
				highway structure designs and site specific considerations, it is not feasible
				to completely standardize the method by which utilities are attached to
				structures. Therefore each proposed attachment shall be considered on its
				individual merits, and shall be individually designed for the specific
				structure.
D. Utility line
				attachments to a highway structure shall not be considered unless the structure
				in question is of a design, age, and physical condition that is adequate to
				support the additional load and accommodate the utility without any compromise
				of the highway features, including reasonable ease of maintenance.
E. Attachment of a pipeline carrying a
				hazardous transmittant to a highway structure shall be avoided whenever
				possible. When such an attachment is permitted, the facility design shall be at
				a level to provide maximum safety.
F. Utility positioning on a highway structure
				which will inhibit access to any structure part for maintenance shall not be
				allowed. Utility access manholes shall not be allowed in a structure deck or
				load carrying member.
G. The entire
				utility installation on a highway structure shall be so located as to not
				reduce the vertical clearance otherwise available above river, stream, roadway
				surface or rails. In general, acceptable utility installations are those
				designed to occupy a position beneath the deck an in an interior bay of an I
				Girder Beam, or within a cell of a Box Girder Bridge. Installations shall
				always be above the bottom of girders on a Girder Bridge or above the bottom of
				the bottom cord on a Truss Bridge.
H. Utility line attachments to the visible
				outer portions of structures are unsightly, susceptible to damage, and shall
				not be permitted unless there is no reasonable alternative.
I. Utility line mountings shall be of
				sufficient strength to carry the weight of the utility and shall be of a type
				which will not rattle or loosen through vibrations caused by vehicular traffic.
				This is a matter of particular concern on steel structures. Utility attachments
				shall be designed to accommodate differences in thermal movements between the
				highway structure and the utility.
J. Where a utility facility is to pass
				through an abutment wingwall or other wall of a highway structure, the utility
				is required to neatly restore the disturbed construction by approved methods
				which shall preclude any leakage of water or backfill through the substructure
				elements. Where such construction is approved, any hole created in the highway
				structure shall be of a minimum size necessary for the installation. The
				annular space between the structure and pipe shall be completely filled with
				grout so as to seal the opening and effectively preclude the leakage of any
				moisture or backfill material through the substructure. Where a pipe or conduit
				is to be sleeved (cased) through the structure, the sleeve shall be tight
				sealed into the opening, and the annular space between the pipe conduit and the
				sleeve shall be sealed with a Department approved material.
K. Acceptable utility attachment methods are
				hangers or roller assemblies suspended from the underside of the bridge deck,
				or from hanger rods clamped to the flange of some superstructure member.
				Bolting through the bridge floor or deck shall not be permitted. Where there
				are transverse floor beams sufficiently removed from the underside of the deck
				to allow adequate clearances for the utility, the Bridge Engineer may consider
				a proposal to support the utility line on top of the floor beams.
L. Clearances of utility facilities from
				bridge members shall conform to all governing codes, and shall be such as not
				to render any portion of the structure inaccessible for any maintenance or
				other highway function.
M. The
				utility shall be required to make satisfactory provisions for lineal expansion
				and contraction of its facility as a result of temperature and pressure
				differentials. Line bends or expansion couplings are generally used for this
				purpose.
N. The utility shall
				restore or repair any portion of the structure or highway disturbed or damaged
				by utility installation or use.
O.
				If weatherall steel is utilized in the highway structure, utility attachments
				shall be of similar material.
P. A
				pipeline carrying volatile fluids, pressurized gas, water or sewage poses an
				element of risk when mounted on a highway structure. When such a carrier is
				placed in a casing pipe of leakproof construction, the hazard to the utility,
				the highway facility, and the traveling public can be minimized. It is good
				practice to case all such pipeline attachments through the highway structure.
				The casing pipe should be carried beyond the back of the structure abutment and
				be effectively vented at each end to detect leakage and prevent possible
				build-up of pressure. In addition, all welds shall be tested by non-destructive
				means.
Q. Where a casing is not
				provided for a pipeline attachment to a bridge, additional protective measures
				shall be taken. Such measures shall include, but are not limited to, higher
				safety factors in design and pressure testing. The safety design factor shall
				be twice that normally used.
R.
				Communication and electric power line attachments shall be suitably insulated,
				grounded and carried in a protective steel conduit or pipe from below the point
				of ground exit, to below the point of ground re-entry. Carrier pipe and casing
				pipe shall be suitably insulated from electric power lines.
S. All pipeline attachments carrying gas or
				liquid under pressure, which by nature of the transmittant might cause damage
				or injury if the transmittant escapes on or in the vicinity of the highway
				structure, shall be provided with emergency shutoff valves of automatic design.
				Such valves shall be placed within an effective distance on each side of the
				structure. Exceptions to this rule may be considered by the Engineer, upon
				written justification submitted by the utility.
T. The responsibility of the utility owner
				requesting a bridge or highway structure attachment cannot be over stressed.
				The utility shall ascertain the extent of the Department's design requirements
				prior to initiating the design for attachment. A Registered Professional
				Engineer experienced in structural design shall be responsible for the design
				effort. Complete plans showing all details of the proposed work, together with
				pertinent design documents shall be prepared and submitted, along with the New
				Mexico Public Highway Utility Accommodation Permit Application. Traffic control
				plans must also accompany the permit. The plans must be complete and adequate
				enough to show in detail the full extent of the proposed work.
U. All materials integrated into the design
				must be certifiable for quality and strength, and full specifications must be
				provided in support of the design.
U. A complete written justification must
				support the need for attachment and demonstrate that there is no viable cost
				effective alternative.
V. All
				components of the utility attachment shall be protected from corrosion. Steel
				components shall be galvanized or painted in accordance with current Standard
				Specifications For Highway And Bridge Construction.