The $4-per-gallon gas prices at numerous stations welcoming residents in the region Tuesday morning were unwelcome -- especially for those with nearly empty gas tanks.

Watching gas prices steadily creep up during the past few months has been an aggravating exercise for residents as they figure out how to get the most gas for their buck and balance the rest of their funds accordingly.

"(Customers) come in crying sometimes," said Kulwant Multani, the owner of the Valero station at the corner of 101st Street and Broadway in Merrillville, where a gallon of gas was $4.05 on Tuesday.

Bill Bush, a spokesman of the American Petroleum Institute, said the cost of crude oil is by far the biggest factor in gas prices. He said with crude oil at least $120 a barrel, the refiners pay at least $2.85 per gallon. Each barrel contains 42 gallons.

"Today there is a good, strong demand for oil worldwide," Bush said. "Even though the United States' demand has leveled, we end up paying the world's market price, and there's a lot of growth in China and India."

Brandon Wright, the manager of communications for the Petroleum Marketers Association of America, said the weakening of the U.S. dollar also plays a role in the increase.

The weakening of the dollar wasn't on the mind of Crown Point resident Sarah O'Conner when she filled up her car at the Valero station. The weakening of her wallet was.

"I'm just thankful I can walk down the street," said O'Conner, who now walks to her job at a local nursing home. "I get everything on sale, and my mom watches my son to save money."

Brad Durham, of Merrillville, filled up his wife's car Tuesday at the Speedway station on the corner of U.S. 30 and Broadway for $59.25.

Gas prices have had an effect on his family's budget as well as his business - the Avis car rental facility at 81 W. 78th Place. Durham said he's seen more rentals of smaller cars but also has seen an increase in business with the rising cost of plane tickets.

AAA spokeswoman Beth Mosher said it is becoming common for families to scale back driving plans as they watch the prices rise. She said more families are expected to stay closer to home this summer.

"Gas prices have an impact on the economy as a whole," she said. "It's a bad circle we're in."