In 2003, tolls were raised on seven bridges across the Delaware River, connecting Pennsylvania to New Jersey.

Question:

In 2003, tolls were raised on seven bridges across the Delaware River, connecting Pennsylvania to New Jersey. In the first two months of the year, bridge traffic fell by 17%, but revenue increased by 123% because of the higher tolls.
What is the price elasticity of demand for using these bridges to cross the Delaware River?