Answers to questions like these can aid you in DWI detection and in your testimony at trial.

Phase One:

What is the vehicle doing?
Do I have grounds to stop the vehicle?
How does the driver respond to my signal to stop?
How does the driver handle the vehicle during the stopping sequence?

Phase Two:

When I approach the vehicle, what do I see?
When I talk with the driver, what do I hear, see, and smell?
How does the driver respond to my questions?
Should I instruct the driver to get out of the vehicle?
How does the driver get out of the vehicle?
When the driver walks toward the side of the road, what do I see?

Phase Three:

Should I administer field sobriety tests to the driver?
How does the driver perform those tests?
What exactly did the driver do wrong when performing each test? What did he do right?
Do I have probable cause to arrest for DWI?
Should I administer a preliminary breath test?
What are the results of the preliminary breath test?