LA CROSSE, Wis. (WKBT) -

One of the most common duties for a police officer can also be one of the most dangerous. A traffic stop can be for something as simple as speeding, but it is anything but routine.

No one likes to be pulled over, it can be frustrating and nerve wracking. But for the officer it can be very unpredictable. The Citizen's Police Academy class was put through a series of scenarios to see how a traffic stop works, and how quickly it can change.

Anyone who has been pulled over by police has heard this before, 'Can I please see your I.D.?' It's a standard question for something that happens daily, a traffic stop. But just because it's common, doesn't make it routine.  "We have no idea what we're walking up on when we come up to that driver's side window," said Lt. Dan Kloss from the La Crosse Police Department.

What starts as a speeding stop can quickly end in violence, so officers need reliable habits for every stop to keep themselves safe. For instance, while walking up to the window officers touch the back of the car, creating a finger print in case it's needed for evidence later.

Officers check your backseat for people or weapons. Even where they stand, behind the driver and out of traffic can save an officer's life. All things the department hopes are second nature. "A routine traffic stop can turn upside down in a matter of seconds," said Lt. Kloss, "and they need to be able to recognize threats before they actually have them taken out against them, and what the human element presents in any type of situation is the unknown."

The academy class learned about that human element first-hand. In one scenario tension ran high as the driver confronted the officer. The driver eventually got back in the van without incident, but that tension created tunnel vision, causing the class member to miss a gun sitting right on the dash.

In another the class saw just how quickly things can escalate, with a driver exiting the vehicle with a gun and pointing it at the officer.

Many police officers will admit, the majority of the time the worst they face is an angry diver, but that doesn't change how they handle each and every stop. "It's not that the officer is on edge or is nervous or is anxious about you or your activity," said Lt. Kloss, "they just don't know what's going to happen and so they have to make sure that they go home to their families at night."

Every few months the department randomly pulls dash cam video of traffic stops for all officers as part of ongoing training.

This week's academy class also included a driving lesson. The class drove the squad cars and SUV's through a driving course, with all the blind spots in the vehicles, it's not as easy as it looks.

There is one week left in the class.  Next week the class will learn about how to handle an active shooter in an office or public place. Each class member also gets to do a ride along on third shift to see what overnight's are like for officers.