Reaction around the country to the horrific tractor-trailer and car crashes on Florida's Interstate 75 this past weekend continues to pour in to the area.

The crashes north of Clermont took 10 lives when fog and smoke combined to make a stretch of I-75 deadly early Sunday morning.

Around the country, people are asking when it's appropriate for state troopers to shut down a highway.

Florida officials interviewed by the Associated Press pointed out that drivers are ultimately the ones responsible for driving safely in poor conditions.

There are no federal guidelines on when local officials are to close roads due to dense fog, smoke or dust storms.

Those kinds of decisions are left to local officials, who are in turn typically dependent on state troopers on the scene to help make the call on when to shut down a highway and when to reopen it.

In addition to motorist safety, one factor officials weigh is the cost to trucking companies of highway shutdowns.

In the I-75 case, a district lieutenant in Gainesville who was on the highway made the call to reopen the road after it had been shut down for three hours.

Shortly after it reopened, the horrific collisions between cars and 18-wheelers began to take lives.

Another factor used by Highway Patrol officers in the decision-making process is information and forecasts from the National Weather Service.

Perhaps the most important factor for the troopers is what they can and can't see.

"If I'm a road sergeant and I go to the scene and can't see anything, I call up and I say, 'Hey, we're closing the road,'" a spokesperson said.

State officials have not yet indicated if they will change protocols on road closures in the wake of the I-75 crashes.

Source: Associated Press: "Few guidelines exist on when to shut down roads," Mike Schneider, Jan. 31, 2012