Section 47 (inserted by section 11 of the Act of 2004) of the Principal Act is amended by inserting after subsection (2) the following:
"(2A) In a prosecution for an offence under this section, it is presumed, until the contrary is shown by the defendant, that the speed limit indicated on a traffic sign is the speed limit that has been applied under this Act to the road when the offence is alleged to have been committed.".