Greeley and Highlands Ranch will be the first sites in Colorado, and among the few nationwide, to have fully automated, computerized gasoline stations.

A spokesman for Gary-Williams Retail Co., which will own and operate the stations, said they will be run from a remote location.There will be no station attendants and no place to buy snacks or get a car washed. The new stations will provide only fuel.

"You don't have to leave the side of your car," said Tim Howard, the construction and operations engineer for Gary-Williams. "It'll be much faster. You don't have to stand in line behind people waiting to buy cigarettes and pop."

The gasoline pumps will accept credit cards or cash. If customers have problems, there will be an "800" number for help.

For a while after the stations open, customer-service representatives will be available. Mr. Howard said a full security system will include video surveillance and alarms.

The company will benefit from lower labor costs and having a simpler operation to run because gasoline will be the only product, Mr. Howard said. But he said there won't be significant job losses.

Although the company will hire fewer clerks, more maintenance will be needed to check the stations and make repairs.

Gary-Williams also has made a substantial investment in environmental controls that are "beyond any regulations required by the Environmental Protection Agency," Mr. Howard said.

Among other things, the stations will have vapor-recovery systems, double- walled storage tanks and piping systems and electronic leak detectors.

The parent company of Gary-Williams Retail Co., Gary-Williams Energy Corp., is an independent Denver-based company that began in oil exploration 40 years ago and moved to refining. This is the company's first retail gasoline operation.

Mr. Howard said there are only a few such gasoline stations in other states: one each in Montana and Texas and a couple in Nebraska.

John Bennitt, a Conoco spokesman in Denver, said his company has a similar service for night hours but doesn't plan to do away with daytime clerks.

He said there is a class of customers, particularly fleet owners, taxis and other commercial vehicles, that wants to fuel quickly. But "there are other people who frankly want to see another human face," he said. "For them, it's important to have that option."