Chicago has some of the highest gas prices in the country.

AAA offers insurance to motorists and keeps an eye on gas prices for its customers. It reports that Chicago’s gas prices are averaging around $4.50 per gallon. That’s up about 20 cents since last week.

“In May of 2011, it was $4.65 for Chicago, so we’re not the highest yet or the highest that Chicago has ever seen yet, but we’re getting increasingly close,” said Beth Mosher, Chicago spokesperson for AAA.

Mosher said she doesn’t know if the region will hit $4.65, but trends show prices rise in the spring and summer.

Meantime, Patrick DeHaan, Senior Petroleum Analyst for gasbuddy.com, believes gas rates will continue to rise until May. Dehaan said there are a few different factors for the rise, including the high demand for gas during warm weather and geopolitical tensions, such as the United States’ current conflict with Iran. However, he also attributes some of Chicago’s gas price increase to the switch from winter gasoline.

“Think of it sort like a clearance sale. We have an old product—winter gasoline that’s being clearanced out. And as that clearance occurs, new merchandise—more expensive merchandise—summer gasoline is hitting the shelves or in this case hitting the pumps,” he said.

Dehaan said the city generally makes a transition from winter fuel which has higher volatility levels to lower reformulated gasoline because it meets EPA pollution standards for the summer months. He said he encourages drivers to shop around for best gas prices. 

Both Dehaan and Mosher advised users to slow down to save money on gas.

“For every five miles per hour someone goes over 60 [miles per hour], that’s like adding 24 cents to the gallon.” said Mosher.