(1) The general controls relative to pipelines shall apply to underground installation of power and communication lines.

(2) The general controls set forth in WAC 468-34-270 relative to installations on highway structures shall be followed.

(3) The design of underground installations should reflect consideration of possible future highway and/or utility enlargement.

(4) Manholes shall be designed and located in such a manner that will cause the least interference to other utilities and future highway expansion.

(5) New underground utility installations may be permitted in scenic strips, overlooks, where they will not require extensive removal or alteration of trees visible to the highway user or impair the visual quality of the lands being traversed.