49 CFR 240.104: Criteria for determining whether movement of roadway maintenance equipment or a dual purpose vehicle requires a certified locomotive engineer.

(a) A railroad is not required to use a certified locomotive engineer to perform the following functions:

(1) Operate specialized roadway maintenance equipment; or

(2) Operate a dual purpose vehicle that is:

(i) Being operated in conjunction with roadway maintenance and related maintenance of way functions, including traveling to and from the work site;

(ii) Moving under authority of railroad operating rules designated for the movement of roadway maintenance equipment that ensure the protection of such equipment from train movements; and

(iii) Being operated by an individual trained and qualified in accordance with §§ 214.341, 214.343, and 214.355 of this chapter.

(b) A railroad is required to use a certified locomotive engineer when operating a dual purpose vehicle other than in accordance with paragraph (a)(2) of this section.