Police officers can't initiate a traffic stop just because they feel like it. Instead, their reason for the stop has to meet or exceed the standard of reasonable suspicion. This isn't as strict as probable cause, so you shouldn't confuse the two standards. 

It's sometimes possible to call the reason for the stop into question. Before you do that, you should understand what reasonable suspicion means. 

What's reasonable suspicion?

Reasonable suspicion means that the officer saw something that led them to believe that you were impaired. This must be something that would lead any reasonable person to think the same thing. Some examples of reasonable suspicion to initiate a traffic stop for drunk driving include seeing a driver:

• Weaving in and out of lanes
• Stopping suddenly without cause
• Driving too slow or too fast
• Failing to obey traffic signs or signals
• Turning illegally without a signal
• Hitting or almost hitting things on the side of the road

Once the officer stops the vehicle, they'll try to determine what's going on with the driver. They may conduct a field sobriety test or a roadside breath test to determine whether the person is impaired or not. If this shows impairment, an arrest for drunk driving will occur.

There are many factors that come into the picture when you're trying to determine what defense strategy you should employ for a drunk driving charge. There are some instances in which the cause of the traffic stop might be one point you can use. Developing your defense can be challenging, so be sure you're drawing on the knowledge of someone who's familiar with these matters.