Rock Springs, WY – With rising gas prices, there are more reports of people not paying when they fill up their cars. In the Rock Springs-Green River area, a company is trying to combat the problem by requiring customers to pre-pay for their gas, starting May first. Red Horse Oil runs five gas stations and Vice President of Sales, John Bunning, says some locations have seen as many as 10 drive-offs a month over the last six months. And while they'd rather not make people pre-pay, he says they don't feel like they have a choice. Bunning says in Wyoming, it's easy to think people are honest and won't steal. But he says they found out the hard way that isn't necessarily the case. Bunning admits this is an inconvenience for their regular customers, many of whom have already expressed their opinions about being forced to pre-pay. But Bunning says it's better then having to increase gas prices further to make up for money lost to drive-offs.