67 Pa. Code § 15.2
The vehicles enumerated in this section are designated as authorized vehicles of the type indicated. They may be equipped with one or two flashing or revolving yellow lights as provided in 75 Pa.C.S. § 4572(b) (relating to visual signals on authorized vehicles), and as defined in Chapter 173 (relating to flashing or revolving lights on emergency and authorized vehicles), except that school buses shall be equipped with red and amber flashing lights as defined in 75 Pa.C.S. § 4552 (relating to general requirements for school buses). The flashing or revolving yellow lights on all authorized vehicles except school buses shall be activated only when the vehicle is performing the type of work which is the basis of the designation of the vehicle as an authorized vehicle, except lights on Type VI vehicles may be activated whenever an emergency condition requires police assistance. The enumeration of vehicles is as follows:
(1) Type I. Type I vehicles include the following:
The provisions of this § 15.2 adopted March 17, 1978, effective March 18, 1978, 8 Pa.B. 759; amended May 25, 1984, effective May 26, 1984, 14 Pa.B. 1807; readopted April 21, 1989, effective April 22, 1989, 19 Pa.B. 1736; amended November 20, 2015, effective November 21, 2015, 45 Pa.B. 6687. Immediately preceding text appears at serial pages (250317) to (250318).
This section cited in 67 Pa. Code § 15.3 (relating to special operating privileges); 67 Pa. Code § 173.3 (relating to display requirements); and 67 Pa. Code § 179.10 (relating to general conditions).