Back before there was a United States, each of the colonies along the Eastern Seaboard had its own set of tariffs on items imported from other colonies.

The practice wasn't outlawed until the Constitution assigned to the Congress all matters pertaining to interstate commerce.

Now, some states have come up with a way to zing residents of other states who dare cross their borders. The modern form of the state tariff on interstate commerce is a discount awarded to in-state residents who purchase E-ZPass transponders from state authorized tolling authorities in that state. Out-of-state drivers, who purchase their E-ZPass through tolling authorities in their own states, subsidize the discounts.

For example, according to a survey by the AAA Auto Club, Rhode Island residents pay 83 cents to cross the Pell Bridge, whereas out-of-state drivers are charged $2 per axle. A driver who purchases a transponder through the New Jersey Turnpike can travel the full length of that toll road for $10.40 (off-peak), while an out-of-state E-ZPass user would pay $13.85. New York City's Metropolitan Transportation Authority charges local purchasers $4.80 to cross the Robert F. Kennedy, Bronx-Whitestone and Throgs Neck bridges or use the Brooklyn-Battery and Queens-Midtown tunnels; others pay $6.50.

None of the agencies involved post any information about the discounts. Instead, they post only cash toll prices.

E-ZPass discounts are supposed to reward users for reducing the toll system's costs and mitigating congestion and resultant pollution and safety problems around toll areas. Charging higher tolls to out-of-state drivers is a hidden form of taxation that should be outlawed.

Governors of the 14 states in the East and Midwest that use the E-ZPass system should form a compact that guarantees fair E-ZPass assessment for all drivers, regardless of their addresses.