Even before Labor Day weekend, state troopers had already made more than 40 percent more drunken-driving arrests than last summer.

And experts were predicting an increase in people traveling in Colorado this holiday.

More than 550,000 Colorado residents, or an increase of 3.2 percent over last year, were expected to travel during the holiday weekend.

It’s the most Labor Day traveling since before the recession, according to Wave Dreher, spokesperson for AAA Colorado.

The ones who are driving drunk are the target of this summer’s sustained law enforcement campaign

, said Trooper Josh Lewis, spokesman for the Colorado State Patrol.

“The Labor Day weekend is kind of the last hurrah,” Lewis said. “As much as we’ve publicized the 100 Days of Heat campaign and despite the consequences, people still go out and do what they want.”

Last year, troopers and other participating police officers and sheriff deputies involved in the 100 Days program arrested a total of 1,440 suspects, Lewis said.

This year they have already made more than 2,000 arrests before the Labor Day weekend started. The officers will continue to make arrests until 3 a.m. Tuesday.

“We’re still out there and we’re going to make more arrests,” Lewis said. “Labor Day is our big push.”

Even though there were more drunken-driving arrests this summer in Colorado than last year, there were fewer deaths caused by drunken drivers, Lewis said.

“It looks like we got to some people before they crashed,” he said.

Fritz Homann, spokesman for the Colorado Department of Transportation, said traffic through the Eisenhower Tunnel toward Denver was very heavy Monday afternoon.

Homann said during one hour, 2,926 vehicles drove east through the tunnel.

“There have been a heck of a lot of delays … no accidents, just slow going,” Homann said.

Kirk Mitchell: 303-954-1206, kmitchell@denverpost.com or twitter.com/kmitchelldp