Traffic Law and Enforcement
The Vehicle Code Rewards Precision
Traffic questions blend statutory elements with stop procedure.
Concepts: reasonable suspicion of a civil infraction justifies a stop, and a pretext does not invalidate an objectively supported stop; the scope of the stop is limited to its reason plus safety concerns. Michigan Vehicle Code (MCL chapter 257) definitions matter: careless driving is a civil infraction, while reckless driving requires willful or wanton disregard for safety. The basic speed law sets 25 mph in residential and business districts unless posted, 55 mph on other roads unless posted, and up to 75 on freeways.
OWI requires operating a motor vehicle on a highway or other place open to the public with impaired ability or a BAC of .08 or more. Commercial drivers are at .04, drivers under 21 face zero tolerance at .02, and a BAC of .17 or more triggers high-BAC enhanced penalties. Under implied consent, a lawful OWI arrest obligates a chemical test; a refusal produces license sanctions rather than a forced draw absent a warrant or recognized exception.
Standardized field sobriety tests are the HGN, walk-and-turn, and one-leg stand. A preliminary breath test supports the arrest decision but is not admissible to prove BAC at trial.
Traps: treating a refusal as a confession; confusing careless with reckless driving; assuming a traffic stop requires Miranda.
Rule of thumb: articulate the violation, then the observations, then the test results, in that order.
Worked example: A driver is stopped for a cracked windshield and smells of intoxicants. The stop is valid and the OWI investigation rests on driving and physical observations.