DES MOINES, Iowa - Higher gasoline prices are contributing to an increase in drive-offs, the Des Moines Register reports. "We have noticed an increase in gas drive-offs since gas prices have gone up. However, the number of drive-offs is not as high as it's been in the past," said Sgt. Chris Scott with the Des Moines Police Department.

In this state where an honor system still exists, convenience store retailers have not been quick to ask for prepayment at the pump. But law enforcement officials highly recommend prepayment requirements as a deterrent to drive-offs.

New technology and more stations offering prepayment options have lowered theft of gasoline, according to police. For example, QuikTrip installed a new security system in its Des Moines area locations six years ago, which virtually stopped drive-offs.

Called PumpStart, motorists scan their driver€™s licenses to get a PumpStart card, which activates the fueling pump. This allows customers to pay inside after filling their tanks, said QuikTrip spokesman Mike Thornbrugh.

By requiring either prepayment or use of PumpStart, thieves can€™t get away with stealing gasoline. Before implementing PumpStart, gasoline thefts at QuikTrip stations cost the company around $12 million each year, said Thornburgh.

Despite the evidence that technology stops most drive-offs, some convenience stores prefer to rely on the honesty of its customers. "At Kum & Go, we firmly believe people are trustworthy," said spokeswoman Catherine Huggins. The company has no pre-pay policy in place.

Sometimes not paying is attributed to faulty memory. Across the country, police who stop motorists who have left without paying for their fill-up say frequently the reply is the driver forgot to pay, said NACS spokesman Jeff Lenard.

"The level of forgetfulness is directly related to the price of gas. It seems more than coincidence that it increases when prices increase," said Lenard.