I know PA Governor Wolf signed the Uber/Lyft bill(aka Act 164, aka senate bill 984) on Nov 4, 2016.
I know this PA bill made Uber and Lyft legal instantly on Nov 4, 2016.
It seems like if you drive in Philly, then you need to have one decal in the front passenger side of windshield and another one in the back of windshield as well.
But I can't find the date when PPA must enforce the decal/placecard.
On the other side of the river, NJ drivers must display ONE decale on front passenger side of windshield, starting on May 1, 2017.