This subpart applies to:

(a) New utility installations within the right-of-way of Federal-aid or direct Federal highway projects,

(b) Existing utility facilities which are to be retained, relocated, or adjusted within the right-of-way of active projects under development or construction when Federal-aid or direct Federal highway funds are either being or have been used on the involved highway facility. When existing utility installations are to remain in place without adjustments on such projects the transportation department and utility are to enter into an appropriate agreement as discussed in § 645.213 of this part,

(c) Existing utility facilities which are to be adjusted or relocated under the provisions of § 645.209(k), and

(d) Private lines which may be permitted to cross the right-of-way of a Federal-aid or direct Federal highway project pursuant to State law and regulations and the provisions of this subpart. Longitudinal use of such right-of-way by private lines is to be handled under the provisions of 23 CFR 1.23(c).