Don't Carry in the First Place This goes without saying, but the number one reason drivers are arrested for marijuana possession is simple. They carry in the first place. Remember, it's illegal under both state and federal law to possess marijuana. Your car doesn't have the same constitutional protections against unreasonable searches and seizures like your house or your jeans pocket. Drivers have a reduced expectation of privacy while on the road. This means John Q. Law doesn't need a warrant to search your vehicle on the spot when he has probable cause. Even when there is no PC, the police may be able to detain your vehicle for a drug K9 if they have reasonable suspicion that something is up. If you are traveling by car, then you should not carry weed. Don't Commit any Traffic Offenses Always remember this Murphy's Law: you can't break two rules at the same time when it comes to driving and carrying. If you have marijuana in the car, then you must obey ALL rules of the road. You must have a valid driver's license and your vehicle registration must be current. All equipment, head lamps, license plate lamps, turn signals, muffler, etc., must be in working order. No illegal plate frames or cracked windshields either. You can't speed, tailgate, roll through a stop sign or commit any other violation in front of an officer because you will be stopped for further investigation. And then it's probably just a matter of time before your stash is discovered. Don't Smoke Before Driving Don't roll any blunts before hitting the road. You may not think your car smells like weed, but it does. In Iowa, the odor of burnt marijuana alone gives police probable cause to search your car. Same goes for the sweet smell of that dank, sticky bud in your center console. Spraying cologne, perfume or some other odorant as the officer approaches will only peak his interest. Keep in mind, too, the officer is probably going to process you for DUI even if you no longer feel the effects from smoking earlier. Iowa has a backdoor prohibition against marijuana use when it comes to DUI. You don't need to be high to be convicted. You just need to have "any amount" of a marijuana metabolite present in your urine. The inactive, non-impairing metabolites of THC can be detected for days. It's a great way to get two charges for the price of one traffic stop. Don't Engage the Officer in Small Talk If the officer brings you back to his car to process the citation, then you should keep a few things in mind. Always be polite, but don't engage in any small talk. It may seem to be a harmless way to pass the time, but everything you do, from your breathing pattern, eye contact and other mannerisms to the story of your whereabouts that day, is being evaluated by the officer to determine whether there is a reasonable suspicion to expand this traffic stop for speeding into a drug interdiction investigation. Don't volunteer information. When he returns your license, insurance and registration forms, you should ask if you are free to go. If the answer is yes, then bounce. If no, then tell the officer that you are choosing to remain silent and you want a lawyer. These are important constitutional rights that you must exercise in this situation. Say the magic words and then shut it. Don't say anything else. Don't Consent to a Search Maybe your stash is stored in a glass jar with a tight-fitting, teflon-lined lid. You've concealed it in a backpack in your trunk and the officer is clueless that you are carrying. But after the officer returns with your speeding ticket for two miles over, he then asks if you have anything illegal in your car and whether you mind if he takes a look around. The answer is simply NO. NEVER CONSENT TO A SEARCH OF YOUR VEHICLE! Why is the officer asking for permission to search? It's because he has NO other lawful reason to search your car. If you consent while carrying marijuana, then you have just given the officer permission to seize your half ounce. Don't think he won't find it. Also, forget the reverse psychology BS. The officer isn't going to change his mind because you assert you have nothing to hide. You might avoid being arrested and taken into custody, but you won't avoid being charged. Even if you weren't carrying, do you honestly know there's no other contraband in the car? Some shake on the floor? Yes, you can be charged for shake; Iowa is an "any amount" state. What if a friend's Adderall pill fell under the seat or, even worse, the prior owner's own stash was tucked in some crevice in the backseat and forgotten? You simply don't know. Either way, you now own whatever is discovered. Bottom line: never consent to a search.