Gasoline prices hit a four-year high in Chicago Wednesday, where the average price for a gallon of regular unleaded fuel hit $1.99.

The AAA’s Daily Fuel Gauge Report says that's 40 cents higher than a year ago and the highest price in the city since June 2000.

AAA says the statewide average Wednesday was $1.91, that’s roughly ten cents more than just last month.

Experts say a combination of factors led to the increase. They include a higher demand for oil, and motorists beginning to hit the roads for summer vacations.

Nationally, the average price hit $1.84, 33 cents more than last year.