HAMPTON, N.H. – There wasn’t even anyone there to wave goodbye.

After a sunny weekend in northern New England, tens of thousands of tourists headed back to their workweek and their homes to the south Sunday night, passing swiftly and freely through unmanned tollbooths on Interstate 95.

Normally on Sunday nights, southbound vehicles back up for miles at the toll plaza in the middle of New Hampshire’s 19-mile section of I-95. The interstate is the only direct conduit between heavily populated states to the south and the woods, lakes and coastline of New Hampshire and Maine.

But in a six-week experiment to try to reduce at least half the weekend snarls – while maintaining the same toll revenue – officials doubled the $1 toll for northbound passenger cars and eliminated the southbound toll.

“The traffic was definitely lighter,” Glenn Delross said at a highway rest area after passing through the toll Sunday night.

Delross, of Providence, R.I., was returning from a vacation in Maine. He said on previous trips he’d been delayed at least a half-hour at the tolls.

“I’d rather pay double and miss the traffic,” he said.

On Sunday evening, southbound traffic flowed smoothly through the toll plaza. Some drivers even appeared to be traveling faster than the 35-mph speed limit in the plaza area.

The booths were left unmanned so drivers wouldn’t hesitate, Department of Transportation spokesman Bill Boynton said.

Transportation officials planned to review weekend traffic counts from secondary roads to see how many northbound drivers got off the interstate to avoid the increased toll.

Boynton said a few truckers complained the experiment is a raw deal for them. These truckers drive routes that pass through the northbound toll but not the southbound. A trucker who drives a route from Massachusetts to Portsmouth, then over to Concord or Manchester and returning to the Bay State via Interstate 93, for example, would pay a double toll at Hampton but realize no benefit from the experiment.

The experiment was pushed by Gov. Craig Benson, who was caught in an hourlong traffic jam at the tollbooths recently.

The state’s Executive Council approved the experiment Thursday, and it began less than 24 hours later.

The Hampton toll plaza took in $23.4 million last year.