(Cleveland)- Gas prices are heading higher just in time for the summer travel season. Erica Bowman, Chief Economist at the American Petroleum Institute, said prices in the Cleveland are slightly down as compared to this time last year. She explained environmental regulations put into place each summer to meet ozone requirements are a contributor to the higher gas prices. If the gasoline is more expensive to make, it's going to raise the price for consumers. Bowman also said the fluctuation of summertime gas prices also depends on what the crude oil markets are doing.