Back in the 60s I worked at an auto plant in Ohio. There were always guys in the parking lot at shift change selling low tax cigarettes from Kentucky out of their car trunk. And that was when the price difference was in pennies.
I can see the same thing happening in Philly. Retailers will see their volume plunge and not just on sodas. People will buy all their other stuff where they can get the low tax soda.
They need to put checkpoints at the ends of the bridges and search the cars coming over from New Jersey.