KANSAS CITY, Mo. — Trucker Jeff Kolkman was an ace within Green Transportation’s squadron of “road pilots.”

Kolkman was, his dispatcher said, “a very safe driver who followed the rules. He always put safety first.”

Until one spring afternoon when he didn’t.

In a dashcam recording from inside the cab of a 2016 Volvo semi, Kolkman stares down at a black tablet computer in his right hand while driving the 18-wheeler down the interstate at 70 mph. It ends seconds later as the truck slams into the rear of a 2014 Toyota Camry stuck in traffic outside West Terre Haute, Ind.

Kolkman’s big rig never braked, one witness told the state police. It “barely slowed down,” said another.

Four people were killed in that crash near the Illinois-Indiana border last year, adding to a grim toll: fatal truck wrecks are growing almost three times the rate of deadly crashes overall.

More than 4,300 people were killed in accidents involving semis and other large trucks in 2016, a 28 percent increase over 2009, according to the federal government.

“Those should be eye-opening numbers,” said John Lannen of the Truck Safety Coalition. “If air carriers or railroads reported similar numbers, there would be national outrage.”

Yet the National Highway Traffic Safety Administration, the federal regulatory agency responsible for protecting us from danger on the nation’s roads, has not mandated changes that over the past two decades might have averted thousands of rear-end truck crashes like that one outside West Terre Haute.

“They are absolutely a culpable villain in this picture,” said Steve Owings, who co-founded the advocacy group Road Safe America after his son was killed in a rear-end truck collision outside Atlanta 15 years ago. “We need to hold them accountable.”

The Kansas City Star found that NHTSA has largely ignored repeated pleas from the National Transportation Safety Board to take action to prevent trucks from rear-ending other vehicles. While big trucks collide with cars in a variety of ways, experts say these types of wrecks are among the most devastating and yet perhaps the easiest to prevent with technology.

On at least 10 occasions since the late 1990s, the safety board recommended that NHTSA require forward crash avoidance and mitigation systems on all heavy trucks.

Two decades after the safety board first sounded that alarm, NHTSA has yet to publish a proposed regulation, much less put one in effect.

“Many of these crashes could have been mitigated, or possibly even prevented, had rear-end collision-avoidance technologies been in place,” the safety board said in a scathing 2016 critique of NHTSA.

It’s not as if the technology is groundbreaking, or unfamiliar. Many new cars come equipped with automatic emergency braking and forward collision warning systems, among other high-tech safety features.

The auto industry promises that by 2022, such safety equipment will be standard on all new passenger vehicles sold in the United States.

Makers of heavy trucks, on the other hand, have made no such commitment. As a result, only a small percentage of semis on the road today have collision-avoidance technology.

While some large trucking companies are willing to shell out a couple of thousand dollars for the optional equipment when updating their fleets, others would rather not add to the $150,000 cost of a new Kenworth, Freightliner or Peterbilt.

Some in Congress say it’s time to act. Sen. Cory Booker, D-N.J., said the rising death toll from truck accidents is proof that such safety concerns shouldn’t be left to market forces.

“Safety mechanisms for the trucking industry have not kept up with the pace of technological advancement,” Booker said. “It’s time that Congress take meaningful action to improve safety across our transportation sector.”

Motorists on today’s crowded highways are even more vulnerable to being rammed from behind by an 18-wheeler in a work zone or traffic jam than they were a decade ago. It’s only going to get worse in the decades ahead as freight shipments by truck climb to meet the needs of a growing economy and a consumer culture that does much of its shopping online.

NHTSA won’t say why it has not followed through on NHTSA’s recommendations.

Robert Kreeb, a division chief who has been involved in much of NHTSA’s crash-avoidance research, referred all questions to the agency’s communications department. It provided a written statement that said NHTSA is still studying the technology.

“NHTSA researched early systems from 2013 to 2016, and is currently studying next-generation AEB (automatic emergency braking) technology through a naturalistic driving study using a field operation test,” the agency said. “NHTSA expects to complete the critical field operation testing in 18 to 24 months. This research and other information will help inform an agency decision on next steps.”

Safety advocates call that “paralysis by analysis,” and say motorists would be better served if NHTSA moved forward with technology that’s been proven to save lives instead of committing so much of its limited resources on things like driverless cars. The European Union began requiring crash-avoidance systems on big trucks some three years ago.

“It’s all being pushed off by this need to focus on this thing in the future,” said Jason Levine, executive director of the Center for Auto Safety in Washington.

The priority should be on saving lives now, said Jim Hall, who was National Transportation Safety Board chairman when the board first pushed for trucks to have crash-alert systems in the late 1990s.

“Our government has failed to fund safe roads and encourages 80,000-pound trucks on the same highways as families and children in 3,000-pound vehicles,” Hall said.

Why not mandate, he said, “available technology to provide safety to those who fund the highway system — the taxpayer?”

Today’s crash-avoidance systems were designed to compensate for human failure and misbehavior. According to the safety board, speeding, distracted driving and impairment are, in that order, the three leading causes of fatal wrecks.

Truck crashes have become deadlier as speed limits have risen across the country, because even today’s well-built cars with all their safety features are no match for the lethal mass of a semi traveling at high velocity.

Forty-three states have maximum speed limits of 70 mph or above, compared to 35 states a decade ago. In seven states, 80 mph is now the limit on interstates; only two set it that high in 2008.

“Surviving a crash becomes less viable at about a 45 mph impact and it starts to go up pretty exponentially,” said Capt. Chris Turner, who heads the truck safety program for the Kansas Highway Patrol.

Our roads are also more clogged with traffic now than a decade ago, increasing the potential for more wrecks.

Today’s forward collision-avoidance systems can prevent more than seven out of 10 rear-end truck collisions, according to companies that have deployed the equipment in their fleets. When wrecks do occur, injuries are generally less severe and property damages are lower, findings that NHTSA does not dispute.

“The silver bullet out there right now is automatic emergency braking,” said Jeff Burns, a Kansas City attorney who specializes in truck wreck cases.

At least 300 people die and 15,000 are injured annually in wrecks where a semi runs into the back of another vehicle, according to a University of Michigan Transportation Research Institute study.

Since the summer of 2017, three rear-end truck crashes very much like the one in Indiana killed eight people in the Kansas City area: five in a single wreck on the Kansas Turnpike near Bonner Springs on July 11, 2017, one that same month on I-435 in Overland Park, and then in February two along that same stretch of interstate when a semi hit a minivan near State Line Road. Both of those victims were children.

All three wrecks might have been averted if the semis that crashed into slow-moving traffic had automatic emergency braking.

The NTSB has long insisted on the need for forward crash-avoidance systems in large trucks. This year, the safety board again included automatic emergency braking systems for trucks on its annual list of “Most Wanted Transportation Safety Improvements.”

But the independent agency has limited authority. It can only investigate commercial vehicle crashes and make recommendations on preventing them.

The agency has no power to impose rules. That authority rests with Congress and federal regulatory agencies such as the National Highway Traffic Safety Administration.

Jim Hall was shocked at NHTSA’s lack of urgency on the matter when, in 1997, the agency said it had no plans to test the systems in large trucks after the safety board first suggested doing just that. Hall, then the NTSB chairman, told a Senate committee two years later that the safety board was “disappointed” in the agency’s attitude. He has seen nothing to change his opinion since.

“I am even more disappointed today than I was in 1999 over the lack of leadership and safety culture at NHTSA,” he said.

NHTSA is notoriously slow to act. Its bureaucrats and scientists can spend decades studying an issue before proposing a new safety requirement, only to drop it suddenly.

One example that especially galls highway safety advocates: In 2006, the agency began considering a proposal to require use of a mechanism that limits the speed of big trucks and to set that limit at 68 mph. It would not have added a dime to the price of a new truck and would have prevented an estimated 1,115 fatal crashes every year, according to NHTSA’s own estimates.

But after 11 years of consideration, the agency shelved the rule last year in response to industry complaints and a Trump administration edict blocking most new regulations on business.

Even when NHTSA does act, it can take a very long time. Decades passed before NHTSA got around to setting height and strength standards for the bars that hang from the tail ends of truck trailers that help prevent the roofs of cars from being sheared off when they rear-end trucks.

So the fact that 20 years have gone by without the agency moving forward on requiring crash-avoidance systems is not all that unusual, according to auto safety activists like Janette Fennell.

“You see this over and over and over again,” said Fennell, founder of KidsAndCars.org, which pushed NHTSA for years to comply with a congressional mandate that all cars have backup cameras.

A decade passed before they finally did this year, and Fennell says the parallels with truck safety regulation delays “are uncanny.”

“Lives are being needlessly taken,” she said.

Weeks apart along the same stretch of Georgia interstate, 10 people were killed in two rear-end semi truck crashes. Horrified by the loss of life, a congressman from suburban Atlanta introduced a bill he hoped would prevent similar carnage.

Had it passed, Rep. Hank Johnson’s Safe Road Act of 2015 would have forced federal regulators to write a rule requiring automatic emergency braking systems on all heavy trucks.

But as a Democrat in a Republican Congress, Johnson’s bill was dead on arrival in the House, as was a similar one introduced by Sen. Cory Booker, D-N.J., that same year.

Still, the bills’ supporters remained hopeful, because NHTSA chose that moment to take what at the time seemed like a step forward. Four safety groups had asked the agency to begin the long process of writing a regulation requiring that all large trucks be equipped with forward collision-avoidance and mitigation systems.

NHTSA made no promises, but accepted the petition for rulemaking and published an endorsement of sorts in the Federal Register, agreeing that the systems “have the potential to save lives by preventing or reducing the severity of rear-end crashes.”

Then nothing happened.

In the three years since, there have been no hearing notices or invitation for public comments, much less a proposed rule, which doesn’t surprise Joan Claybrook.

“When I was NHTSA administrator in the 1970s,” she said, “I had to push like heck to get anything done.”

No one knows the agency better inside or out. Before she headed NHTSA under President Jimmy Carter, Claybrook teamed up in the 1960s with fellow auto-safety advocate Ralph Nader to push for the legislation that led to NHTSA’s creation.

She said efforts aimed at getting NHTSA to impose a rule requiring automatic emergency braking on trucks is doomed without active support from a strong leader heading the agency.

And there simply haven’t been many over the years, she said, under Republican or Democratic presidents.

A year and a half into Trump’s presidency, an administrator still hasn’t been confirmed and the current nominee, acting administrator Heidi King, has neither a background in highway safety nor solid support so far in the U.S. Senate.

“It doesn’t have any leadership; that’s a problem,” Claybrook said.

Another problem is that the agency lacks a sense of urgency to get anything done, she said. Staffers lack enthusiasm for writing new regulations when they know there’s no support at the top.

Regulators are also subject to pressure from industry groups, which spend a fortune trying to influence policy. Lobbying efforts on behalf of the trucking industry totaled $11 million in 2017, according to the nonpartisan Center for Responsive Politics. That’s in addition to campaign contributions to congressional candidates, overwhelmingly Republican incumbents, which totaled more than $5.2 million in the 2016 election cycle.

“Anything that costs money, the industry usually opposes,” Claybrook said. “Not every single company. But mostly. And it anesthetizes the agency. Unless you have a strong leader in these regulatory agencies who is intent on getting things done, it’s really hard.”

That’s led to a growing trend in NHTSA to broker voluntary deals aimed at achieving the same goals as a regulation, but without any teeth to enforce those aims.

An example was when automakers agreed to install automatic emergency braking on virtually all passenger vehicles by 2022.

While the Obama administration called that deal a great achievement, Claybrook and others were unimpressed because it came without uniform standards or any mechanism to enforce them.

“The whole concept of voluntary standards is a reflection of how broken the NHTSA auto safety rulemaking process is,” said Amit Narang, a policy analyst at Public Citizen, the Nader-founded advocacy group that focuses on auto safety and other issues.

“NHTSA has basically thrown up their hands and said our rulemaking process is just too intense and requires too much cost-benefit analysis.”

Other countries have taken bolder steps. Last fall, South Korea said it would require automatic emergency braking as well as lane-departure warning technology on all new cars and trucks by 2021.

The European Union felt confident enough in the technology that it passed a rule a decade ago that all new big rigs sold in the EU’s 28 member nations come standard with automatic emergency braking as of 2015.

The United States, meanwhile, is still in study mode.

The consequence of not requiring automatic emergency braking systems on trucks was made clear one night two years ago outside of Goodland, Kan.

A Toyota Sequoia was having engine troubles and traveling about 40 mph on Interstate 70 when a semi going the 75 mph speed limit hit it from behind. Six of the 11 people crammed inside the Toyota died.

In a report published this spring, the NTSB spread the blame. The trucker was tired, the agency said. The driver of the SUV had not turned on his flashing hazard lights, and the vehicle was overloaded.

But the NTSB also stressed that the crash might never have happened had the truck driver’s employer paid for the optional collision-avoidance system that the 2016 Volvo tractor was pre-wired for.

Former American Trucking Associations executive Howard Abramson finds it disheartening to think that less than 10 percent of the trucks on the road today have that safety equipment because truck owners are free to go without it.

“When you have 80,000 pounds crashing down the roads full of hundreds of thousands of dollars worth of goods, capable of killing large numbers of people, why wouldn’t you put in a system that costs a couple of thousand bucks?” Abramson asks. “What’s to lose?”

For those in the trucking industry who believe saving lives should be a priority, the evidence is clear, said Steve Williams, a trucking executive who heads a pro-safety industry group called the Trucking Alliance.

As the owner of Arkansas-based Maverick Transportation LLC, he has invested heavily in safety technology over the last couple of decades and seen it pay off.

Fewer wrecks means less money paid out of the company’s self-insurance fund and less spent on repairs and replacement of damaged equipment.

But while the Trucking Alliance — short for the Alliance for Driver Safety & Security — is in favor of the government requiring automatic emergency braking and other safety technology, the group represents only a small fraction of a heavily fragmented trucking industry.

You get different opinions from the industry’s two main lobbying groups.

The more powerful of the two, the American Trucking Associations, is high on the technology, and has been since at least 2015, when the group’s executive director, former Kansas Gov. Bill Graves, called for trucking companies to voluntarily adopt advanced safety technologies.

But he was careful to not come out in favor of a government mandate.

“Our position is the same,” ATA spokesman Sean McNally said recently. “We would like and we would urge equipment manufacturers to make this equipment standard.”

But there are many small firms that might not be able to afford these safety upgrades, he said, and shouldn’t be forced to shoulder that cost.

The other big lobbying group is OOIDA, the Owner-Operator Independent Drivers Association.

According to the Federal Motor Carrier Safety Administration, 86 percent of the nation’s half million trucking companies have fleets with no more than six trucks, and most of them have only one or two.

That’s the constituency OOIDA speaks for, and many of those companies have a hard enough time making ends meet without having to pay more for their trucks, the groups says.

And, some are skeptical about the equipment’s effectiveness.

“We don’t know whether this stuff really works,” said OOIDA President Todd Spencer.

It works, said long-haul driver Mike “Mustang” Crawford of Long Lane, Mo., although he worries about drivers’ increasing reliance on it.

Over the past 24 years, Crawford has driven 6 million accident-free miles without the assistance of any of the new safety technology. But at the truck stops he visits, he’s heard testimonials from his peers.

“I do believe it’s helped stop a lot of accidents,” Crawford said.

Still, he said, “You have to watch what you’re doing, you have to forget Facebook. You have to forget tweets.”

But what if a driver doesn’t heed that advice, like on that day a year ago last May outside West Terre Haute, Ind.? Kiera Davis, whose dad was behind the wheel of the car hit by the trucker, wants more trucking companies to adopt the technology.

But why wouldn’t the government require it?

“It’s taking more lives and it doesn’t need to continue to happen,” she said with notes of anger, grief and disgust. “I would urge them to do something immediately, because it is so preventable.”