When crashes close down part of the highway, it's vital for law enforcement officers to be able to help the victims, protect themselves and keep traffic moving.

One of their most important tools are flares.

There are a couple types of flares: The standard ones we're used to seeing that look like a stick of dynamite and newer battery operated ones.

But, which work better? We asked the experts.

It can take hours officers to clear up the highway after a big crash like this one in Jackson county.

"When I got there, he said give me your flares, I’m running out," says Sgt. Steve Tape with the Wisconsin State Patrol.

The State Patrol uses a type of flare called fusee, and troopers use a lot of them.

"They last about a half hour," Sgt. Tape says.

Most Eau Claire sheriff's deputies also use the fusees. But, some deputies also have turbo and power flares.

They’re "waterproof, you can change the patterns and it's crush proof,” explains Eau Claire County Sheriff's Deputy Mark Lapage. “This flare (the fusee) is a onetime use, these you can use over and over again."

Starting a tenth of a mile away, we approached a mock crash scene first with no flares, then with the battery operated turbos and rechargeable power flares.

"You can set the electric ones up really quickly," Lapage says. "They protect the deputies, they protect the other motorists."

Then we took one last drive past the mock crash with the fusees.

"I really like these,” Lapage says. “People don't like to run over fire."

So which flare works best?

Lapage says the fusees burn hot chemicals.

“If you don't hold them correctly, you can ruin a pair of uniform pants pretty quickly," he says.

But, he says the electric ones aren’t as bright during the day or in bad weather.

"Snow can cover these and you wouldn't see them."

Lapage says each flare has pros and cons, but, he also says he wouldn't feel safe on the side of the highway without them.

They’re "priceless,” he says.

Priceless… but not cheap. The fusees come 72 in a case and cost between $115 and $250 for each case. But, again those can only be used once.

The larger turbos are $225 for a pack of eight and the power flares cost $560 for a pack of six and their charger.