(a) General.

1. (1) Crossings may be encased or uncased dependent upon the needs and conditions identified by the type of highway facility, utility type, utility owner, or the Arkansas Department of Transportation.
2. (2) The department encourages, and will require when determined necessary by the District Engineer, utility owners to extend encasements from right-of-way line to right-of-way line.
3. (3) Crossings shall be avoided at deep cuts, bridge footings, retaining walls, cross drains, or at any other location where attaining the minimum depth of cover as required by this part would be difficult.

4. (4)

   1. (A) Crossings shall be perpendicular to the traffic lanes of the highway where practicable.
   2. (B) Utility owners shall submit justification satisfactory to the department for any utility crossing not perpendicular to the highway alignment.

(b) Crossing methods.

1. (1) Crossings may involve boring, tunneling, or open cut depending on the highway and conditions.
2. (2) Boring shall be by the directional bore method.

3. (3)

   1. (A) Dry bores shall be conducted in a manner consistent with industry accepted practices that minimize annular voids and over-breaks and protect the integrity of:

(i) Ground cover;

1. (ii) Surfaces; and

   1. (iii) Structures.
   2. (B) In no case shall overbore exceed five percent (5%) of the pipe diameter.
   3. (C) The use of water under pressure greater than ten pounds per square inch (10 psi) to jet a hole ahead of the bit is not permitted.
2. (4) Wet boring is not allowed.
3. (5) Bore pits shall be placed outside the highway right-of-way when practicable, otherwise bore pits shall be placed on the edge of the highway right-of-way as far from the outer edge of the shoulder as possible.

4. (6)

   1. (A) Bore pits shall be located and constructed in such a manner as to not interfere with:

      1. (i) Footings of highway structures;
      2. (ii) Safe roadside clearance;
      3. (iii) Pedestrian passage; or
      4. (iv) Traffic operations.
   2. (B) If necessary, shoring shall be utilized.
5. (7) Excavation for bore pits shall not intrude into the flow line of parallel ditches or the slope of embankment sections.

6. (8) Permanent crossings of the highway through drainage structures (box or pipe culverts) are not permitted.

   1. (c) Encased crossings.

7. (1)

   1. (A) Encasements shall be designed to support the load of the highway and superimposed loads thereon and, as a minimum, shall equal the structural requirements for highway drainage facilities.
   2. (B) Encasements shall be composed of materials of satisfactory durability under conditions to which they may be subjected.
8. (2) Encasements shall have a minimum cover of forty-eight inches (48”) measured vertically from the flow line of parallel ditches or sixty inches (60”) measured vertically from the highway surface, whichever provides the greater cover.

9. (3)

   1. (A) On noncontrolled access highways, encasements should extend from right-of-way line to right-of-way line, as practicable, and may be required by the District Engineer in some instances.
   2. (B) As a minimum, encasements shall extend six feet (6’) beyond the toe of the slope in any embankment section, the flow line of any parallel ditches, or back of any curb as applicable for the highway section.
10. (4) Encasement shall be provided under medians and the area between frontage roads and the main lanes.
11. (5) Encased crossings of partially controlled or fully controlled access highways shall be encased the full width of the control of access.

12. (6) All crossings involving frontage roads shall be encased between the control of access and frontage road and the pipe shall extend a minimum of six feet (6’) beyond the toe of the slope in any embankment section, the flow line of any parallel ditch, or the back of any curb as applicable on the side of the frontage road opposite the main lanes.

    1. (d) Uncased crossings.

13. (1)

    1. (A) Uncased carrier pipe shall provide sufficient strength to withstand the internal design pressure and the dead and live loads of the pavement structure and traffic.

    2. (B) Additional protective measures should include:

       1. (i) Increased wall thickness/higher strength material;
       2. (ii) Adequate coating and wrapping;
       3. (iii) Radiograph testing of welds;
       4. (iv) Hydrostatic testing;
       5. (v) Cathodic protection; and
       6. (vi) Other measures as required by 49 C.F.R. pt. 192 or 49 C.F.R. pt. 195.
14. (2) The minimum cover over the uncased carrier pipe shall be forty-eight inches (48”) measured vertically from the flow line of parallel ditches or sixty inches (60”) measured vertically from the highway surface, whichever provides the greater cover.
15. (3) When existing underground facilities are permitted to remain in place, suitable bridging, concrete slabs, or other appropriate measures shall be used for protection when by reason of shallow bury the facility may be vulnerable to damage from highway construction or maintenance operations.

(e) Open cut of paved surfaces.

1. (1) Open cutting of paved highways is not permitted except under certain circumstances.

2. (2) Conditions where open cuts of paved highways may be considered are:

   1. (A) Utility relocations related to a highway reconstruction project;
   2. (B) Urban highways where longitudinal lines are located under the pavement;
   3. (C) Crossings of gravel highways; and
   4. (D) When the District Engineer determines that boring is not possible or feasible.

(f) Temporary crossings.

1. (1) The placement of a temporary line to cross a highway right-of-way shall be permitted through an encasement under the roadway installed in accordance with this part, or it may be placed through an existing bridge opening or through an existing drainage structure with a minimum of twenty feet (20’) of clear waterway opening if approved by the District Engineer.

2. (2)

   1. (A) An exception may be granted to place a temporary line through an existing drainage structure with less than twenty feet (20’) of clear waterway opening providing a drainage analysis is made by a qualified individual and submitted by the utility owner.
   2. (B) The decision whether to allow the use of the drainage structure for a temporary crossing will be made by the department based on the impact of the drainage analysis.
3. (3) Regardless of size, if the department allows the use of any existing bridge opening or highway drainage structure for the placement of a temporary line, the utility owner will be required to assume all responsibility for future damages caused by the placement of the line.