Around Indianapolis, several stations sold unleaded for $4.15 per gallon Tuesday. That has folks changing their routines; staying at home more or driving less.
Yates said since gas hit $4, she has talked to her family about riding the bus to work two or three times a week to save money.
University of Indianapolis professor Dr. Matt Will said prices usually rise through the summer, especially as demand goes up during peak periods like Memorial Day weekend. However, this time, he said the biggest culprit is oil refinery companies are shutting down, because of new environmental regulations.
"We haven't built a refinery in the United States since 1976. Two refineries have shut down recently and a third is in the process of shutting down. They produce half the gasoline for the east coast," said Dr. Will.
While prices tend to fall in the winter, Dr. Will said Americans should not expect that this year. He said the futures market is forecasting that gas will hit $5 per gallon by late winter.
"The current forecast is they will be higher in the coming winter than this summer,” said Dr. Will. “We haven't seen that in about a decade."