The flashing lights in your rearview mirror on I-10 or the 610 Loop produce an immediate physical response — heart rate up, palms damp, a sense of dread. For most Texans the fear is not really about the ticket. It is not knowing where the line is between what an officer can require and what you can decline. A traffic stop is a seizure under the Fourth Amendment. Knowing the boundaries of that seizure is the difference between protecting your record and handing the State the e