concurring:
I concur in the result. Appellant failed to establish that the posted speed limit on Route 6 does not comply with the requirements of the Vehicle Code. See 75 Pa.C.S.A. § 3111(d) (traffic control devices are presumed to comply with the requirements of the law unless the contrary shall be established by competent evidence). While it is not the Commonwealth’s initial burden to offer evidence of a traffic and engineering study in this type of ease, a defendant seeking to challenge the validity of a posted limit must rebut the presumption of validity with competent evidence. See Commonwealth v. Kerns, 278 Pa.Super. 283, 420 A.2d 542, 543 (1980). Here, the Commonwealth’s evidence amply supported the validity of the posted limit on Route 6, particularly in light of the Department of Transportation’s broad discretion in regulating traffic studies. See 75 Pa.C.S.A. § 6105 (department may establish the manner in which traffic and engineering investigations shall be carried out). Further, the PennDOT traffic engineer’s testimony with respect to changes that likely would occur when the road was widened adequately addressed that issue.1
*1139Appellant’s self-proclaimed “expert driver” status is not relevant. He simply failed to prove that the posted speed limit was invalid and now must pay the fine he properly was assessed when he broke the law.
. Like my colleague, I see no prejudice in allowing the admission of the traffic study. The Commonwealth offered a plausible explanation for the error and appellant points to no prejudice he *1139suffered nor any possibly different outcome which would have resulted from his possession of the study at an earlier date.