It's happened. Gas prices hit $4 a gallon Tuesday, a new milestone.

"I can't afford this," Kevin Diaz said.

Unfortunately for Max Coon of Lansing, he's hit a personal milestone he wish he hadn't.

"I spent $100 paying for gas in my vehicle," Coon said.

And $100 doesn't even fill his tank.

"I could have gotten more," he said, "and that's just not cool."

"They promised four bucks a gallon, everyone should have been ready, I guess," Glen Svacha, assistant manager of a Holt Sunoco station, said. "It's not even Memorial day yet, sky's the limit."

He said as prices increase, customers aren't buy as much as they used to.

"Fill-up doesn't roll off the lips as easy as it used to," Svacha said. "It's usually $20 or $30 or $40."

Drivers said it's about time to make some changes.

"It's changed my whole life," Diaz, who just moved to Lansing, said.

"I've become more hesitant to drive," Lansing resident Matt Amthor said.

"I'll be riding my bike to work," Stephanie Edwards of Lansing said.

"If it keeps going up I'm going to have to sell my truck and get a Honda," Coon said.

The Michigan Retailers Association said 54 percent of retailers had decreased sales in March. They couldn't give a specific reason for the decline, but people at the pump said they have a pretty good idea.

"Gas prices," Edwards said. "It's expensive to go to the mall. It's a necessity to get gas, it's not a necessity get clothes."