CLEVELAND -- What was once a team in charge of guiding a freight train is being slashed down to just a single person.

In a push for efficiency, railroad companies are proposing engineer-only crews. Some are already using them.

It's a concern for railroad workers and anyone who sees a railroad track.

Lonnie Swigert is an engineer who lives in Northeast Ohio. When he's at the controls, safety is just one of the thoughts on his mind.

"[You're thinking about] everything. Every slow order, every safety, every rule, every car, every crossing, every person's life that's around your train when you are going by. That's all on you," said Swigert.

It's like driving a car that weighs 15,000 tons. And something as simple as missing your exit, says Swigert, can put an entire town up in flames.

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"If something happens, it could be catastrophic," he said.

Safety on the rails is a system of checks and balances. A freight train used to require a five-person crew: an engineer, a fireman, two brakemen and a conductor.

Advances in technology eliminated the caboose in the 1980s, bringing the crew to just three people. Another position was lost to new union contracts.

Now the conductor could be the next to go, putting the weight of 25 million pounds on just one man.

"It scares me to think that I'd have to do it by myself," said Swigert.

The change, being implemented by more and more rail companies, comes at the same time as rail cargo is also changing.

Cars carrying volatile crude oil have skyrocketed, increasing 4,000 percent in five years from 9,500 carloads to 415,000, according to the Association of American Railroads, AAR.

The AAR also points out that 99.9977 percent of all cargo reaches its destination safely.

But an analysis of federal data by McClatchy DC shows more crude was spilled in rail accidents in 2013 alone than the total of the prior 37 years since the government began tracking spills.

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In February, the U.S. Transportation Secretary Anthony Foxx announced a series of voluntary operating practices for carrying crude. As of July 1, railroads will use a program that considers 27 risk factors to determine the best route for trains with 20 or more cars of crude. This is called the Rail Corridor Risk Management System, or RCRMS.

Also, crude trains will be asked to travel under a 40 mph speed limit in the federally designated 46 high-threat urban areas, which include the greater Cleveland area.

Besides creating efficiency, the argument is technology can support single-man crews with the help of safety features that can slow the train to a stop automatically if something goes wrong.

This is called Positive Train Control or PTC. The AAR says it's designed to prevent train-to-train accidents, derailments caused by speed or accidental track switches.

Another piece of technology called an alerter rings an alarm every minute that the engineer must press to deactivate.

Bob Comer, a nationally respected rail expert, argues there's no machine or guideline that makes up for another person's expertise.

"When you have two people in the locomotive, you have two sets of eyes to look at things, to look at the track, see what they are doing, what's up ahead," explains rail safety expert Comer. "What if you only have one person? Now you've only got one set of eyes. You've only got one brain. And to me the safety [just diminishes] ... and the only reason they would do that is to save money."

"Just like in any industry, things go wrong, and when things go wrong, I want somebody there with me, someone there to help me, someone there to call for help for me," said Swigert.

Just two weeks after a derailment in Lac Megantic, Quebec, killed more than 47 people last summer, Canada outlawed one-man trains for hazardous cargo.

Congress is considering similar action with the Safe Freight Act, House Bill 3040.

But, which tracks government transparency, gives it only a 3 percent chance of passing.

"The railroads are very powerful, and we feel that they are going to water down this issue," said J.P. Wright, who is an engineer as well.

A spokesperson for Norfolk Southern told WKYC trains operating outside of rail yards always have a crew of at least two people.

A CSX spokesperson told us safety is the top priority, and that it "currently operates all mainline revenue trains on two-person crews, but future technology such as PTC should be tested to assess best practices over time," said Carla Groleau, in a statement emailed to WKYC.

Wheeling Lake Erie Railway did not respond to our request.

Without the federal government's support, workers feel like it's an uphill battle, where Swigert worries companies could sacrifice your safety for profits.

"You don't want to be the face of what happened," said Swigert. "I don't want to be that guy."

Swigert and Wright are advocating for people to talk to their congressional leaders and demand some kind of action before the next accident occurs.