14 C.F.R. § 151.13
(a) Landing aid requirements. No project for developing or improving an airport may be approved for the Program unless it provides for acquiring or installing such of the following landing aids as the Administrator determines are needed for the safe and efficient use of the airport by aircraft, considering the category of the airport and the type and volume of traffic using it:
(4) Runway distance markers.
For the purposes of this section “approach lighting system (ALS)” is a standard configuration of aeronautical ground lights in the approach area to a runway or channel to assist a pilot in making an approach to the runway or channel.
(b) Specific landing aid requirements. The landing aids set forth in paragraphs (a) (1) through (4) of this section are required for the safe and efficient use of airports by aircraft in the following cases:
(2) In-runway lighting is required as part of a project:
(i) If the project includes:
(a) Construction of a new runway designated by the FAA as an instrument landing runway for which the installation of an IFR precision approach system including ALS and ILS, has been programmed by the FAA with funds then available therefor;
(b) An extension of 3,000 feet or more (usable for landing purposes) of the approach end of a designated instrument landing runway equipped, or programed by the FAA, with funds then available therefor, to be equipped, with an IFR precision approach system including ALS and ILS;
(c) Reconstruction of a designated instrument landing runway equipped, or programed by the FAA, with funds then available therefor, to be equipped with an IFR precision approach system including ALS and ILS, if the reconstruction requires the closing of the runway; or
(d) Any other airport development on an airport whose designated instrument landing runway is equipped, or programed by the FAA, with funds then available therefor, to be equipped with an IFR precision approach system including ALS and ILS; and
(ii) Only if a study of the airport shows that in-runway lighting is required for the safe and efficient use of the airport by aircraft, after the Administrator considers the following:
(a) The type and volume of flight activity;
(b) Other existing or planned navigational aids;
(c) Airport environmental factors such as local weather conditions and adjacent geographic profiles;
(d) Approach and departure paths;
(e) Effect on landing and takeoff minima; and
(f) In the case of projects under paragraph (b)(2)(i)(d) of this section, whether installing in-runway lighting requires closing the runway for so long a time that the adverse effect on safety of its closing would outweigh the contribution to safety that would be gained by the in-runway lights or whether it would unduly interfere with the efficiency of aircraft operations.
[Docket 1329, 27 FR 12350, Dec. 13, 1962, as amended by Amdt. 151-3, 28 FR 12613, Nov. 27, 1963; Amdt. 151-33, 34 FR 9708, June 21, 1969]