When confronted with mass shootings, we have become conditioned to simply shake our heads and move along. Other than some hand-wringing, predictable cable news chatter, and a run on ammunition, Americans have learned not to expect much.

Fortunately, we are not quite as hardened when it comes to highway massacres.

Less than a month ago, five Georgia Southern nursing students were killed on I-16 when a tractor-trailer slammed into their two stopped cars.

That prompted U.S. Sens. Johnny Isakson and David Perdue to send a note to Transportation Secretary Anthony Foxx.

Since 1992, all heavy trucks manufactured in the U.S. have been equipped with speed limiters – devices to govern the vehicle’s top speed. Since August 2011, the federal Department of Transportation has been contemplating a rule to require those speed governors to be actually turned on and used.

Perhaps it is time to move on a common sense safety measure “that could have reduced the violence of the crash and may have even saved the lives of these five young ladies,” the two Georgia senators suggested last week.

The next day, the transportation secretary called Isakson to say he had moved the speed-governor requirement to the next stage of its long journey. “I’m working hard to promote it,” Isakson said in a telephone interview on Tuesday. “Two-thirds of all truckers are for it. All the major truck lines are for it. The people who are against it are independents – and not all independents are against it.”

Isakson and Foxx were to have a follow-up dinner that night. Perhaps they were still talking when another truck driver on I-16 near Savannah, possibly asleep at the wheel, rammed into another collection of stopped cars. Another five people were killed.

Republicans aren’t usually fans of government regulation. But the Isakson/Perdue endorsement of speed limiters on trucks has resulted in nary a peep of protest.

Mike Collins, for instance, barely batted an eye at the news. Collins is a former GOP candidate for Congress. He lost last year to Jody Hice. He is also the son of former U.S. Rep. Mac Collins.

The Collins family operates a medium-sized, 80-vehicle trucking firm out of Jackson, south of Atlanta. “Am I against regulations? I’m against excess regulations all day long,” Mike Collins said.

But a DOT rule to require the use of speed limiters would have little or no impact on him. His trucks already use them. They’re set to a maximum speed of 68 mph. The same DOT rule that would require the use of speed governors would also require electronic logging of heavy trucks, to keep track of the hours their drivers put in. Again, the bar is low.

“I’ve been doing electronic logs for two years. We went on and did it, and will never look back,” Collins said. “If it’s going to protect my drivers and my trucks, I’m going to take a hard look at it. That’s just good business. I don’t need the government to tell me that.”

But the marketplace isn’t magic. Another reason that Georgia Republicans haven’t closed their eyes to the carnage on our highways might be laid at the Smyrna doorstep of Stephen and Susan Owings, who founded the group Road Safe America after their son was crushed by a tractor-trailer rig in 2002. Cullum Owings was in a stopped car. The truck was on cruise control.

Road Safe America filed the petition to DOT to require activated speed governors on trucks. In 2006.

Stephen Owings credits Isakson for taking up his cause – as well as U.S. Reps. Tom Price and John Lewis, and more recently, Senator Perdue. They have an incentive.

“Georgia is among the five states – and has been for some time – with the most fatalities in crashes involving heavy vehicles,” Owings said. An expansion of the Port of Savannah – connected to Atlanta by I-16 – will only exacerbate the situation.

“Truck traffic is about to double in Georgia. You think we have a problem now? Buckle up,” Owings said.

Road Safe America would like to see Congress demand that the federal bureaucracy complete work on the speed limiter rule within a year. Isakson and Perdue have promised to continue to dog the issue.

But Owings said if we really want to bring heavy rigs under control, we need to reconsider how we pay truckers. The vast majority are paid per mile. They are exempt from overtime pay.

“What are the incentives? Drive as long as you can get away with, and as fast as you can get away with,” Owings said. “We got a formula in this country for exactly what we get.

“Governor Deal got furious with the trucking companies last year during the ice storm because they were the principle cause of the huge traffic jam,” Owings noted. “Well, if truck drivers were paid for every hour they worked, and overtime, those trucks wouldn’t have been moving on that ice.”