How Do Police Know if You are Driving Drunk?
September 12, 2019
As most New Jersey residents are aware, the state has set a general blood alcohol concentration (BAC) limit—applicable to adult, non-commercial drivers—of .08 for driving after drinking alcohol. This applies to anyone found driving drunk, including first offenses, and those with two, three, or more offenses. Drivers under the legal drinking age of 21 can face a DWI conviction if they are caught driving with any measurable BAC, even as low as .01, and commercial drivers can be charged with DUI if they register a BAC of .04 or more. Even worse, if a commercial driver is convicted of a DWI in New Jersey, it may result in the suspension of their commercial driver’s license. Here are some of the top clues that police look for in possible drunk drivers in New Jersey, and defenses that a skilled DWI defense lawyer may raise in court to challenge your DWI charges. If you have been arrested for a DUI, you should consult a qualified DWI attorney who can help fight your case. Our team provides highly effectively defense for driving under the influence of alcohol and drugs in Roselle Park, Linden, Berkeley Heights, Cranford, Springfield, Westfield, and other local towns in Union County, NJ. Contact us now at (908) 838-0150 for a cost-free consultation.
How Much Alcohol until a Person is Too Intoxicated to Drive in New Jersey?
Scientists have been using controlled studies to study the relationship between blood alcohol concentrations and intoxication for purposes of driving for decades. These scientists, also known as criminalists or toxicologists, have administered known doses of alcohol to individuals, measured the BACs of those people, and then tested whether they are able to perform what are called “divided attention tasks” at certain BACs. The term “divided attention task” refers to any activity that involves making several multitasking-type decisions at one time, including driving. Divided attention tasks simulate the complicated number of simultaneous decisions that a driver must make on the road, combining tests of motor skills with reaction times, for example. This is similar to how you as a driver must scan the road in front of you, use your blinker, steering wheel, gas or brake pedals, and make split-second decisions about when to merge, brake, or accelerate.
After scientists performed an exhaustive number of these studies, a consensus emerged that all people, regardless of their size or “tolerance” to alcohol, are too impaired to drive as safely as a sober person at a .08 BAC. Alcohol tolerance simple means how efficiently one’s body eliminate the alcohol, a process which tends to get more efficient as a person’s experience with drinking increases. All people show slowed reaction times, increased risk-taking and poor judgment, and a generally impaired ability to perform divided attention tasks like driving at a .08 BAC or above. Furthermore, scientists have determined that most people are also too intoxicated to drive as safely as a sober person at a .05 BAC for all the same reasons. However, they have not yet reached a consensus on this point, so laws like New Jersey still set the legal BAC limit for driving at .08 for all people. Some states are considering dropping this limit to .05 in the future, and certain drivers, like commercial or underage drivers, must adhere to lower BAC limits in New Jersey.
Top Things Police Look for to Determine Drunk Driving in NJ
Police officers are trained to look for a number of clues that you are driving at a BAC above the legal limit in New Jersey. Obviously, police are trained to identify certain types of poor driving as an indicator that you are too drunk to be on the road. They look for people who are weaving back and forth between lanes, driving without their headlights on at night, or even stopped in a parking lot, on the side of the road, in a driveway, or blocking the road because they have passed out.
Once police identify a car that is violating traffic laws, they will then typically approach the driver and ask a few questions. At this point, they will look for what are called objective signs of alcohol impairment, which include: red and watery eyes, slurred speech, an odor of liquor coming off the person’s breath, poor coordination or balance, dropping or fumbling for driver’s license and registration, and other potential clues of intoxication.
An office observes these objective signs of alcohol impairment, they may ask you to step out of your car and performance field sobriety tests. Some of these field sobriety tests (specifically the walk and turn test, the horizontal gaze nystagmus or “eye test,” and the one-leg stand test) have been scientifically validated or “correlated,” in controlled studies like the ones discussed above, to a certain level of impairment. This means that if you exhibit certain clues on these tests, including losing your balance at certain times, failing to follow instructions, exhibiting certain jerking of your eyes, etc., the police will likely document them in their report. When you head to court for a DWI charge, the officer can testify about your performance on field sobriety tests, regardless of whether you submitted to a breathalyzer test or blood sample that resulted in a formal BAC reading at or above .08%.
Can I Challenge that I was Driving Drunk in a NJ DWI Case?
Your attorney may be able to challenge law enforcement’s evidence regarding drunk driving at trial. If you did not submit to a breath test, a skilled DWI lawyer may be able to argue that your symptoms of impairment were caused by allergies, fatigue, or other factors. They may also be able to argue that your performance on field sobriety tests resulted from poor balance, a preexisting injury (like a knee or back injury), or other causes. If you did blow into the breathalyzer device and registered a formal BAC above the legal limit, attorneys with training on the Alcotest machine (the approved device in New Jersey DWI cases), may be able to invalidate the results by finding issues with the machine itself or how the officer operated it when conducting your breath test.
Need a DWI Lawyer in Cranford New Jersey
If you are facing DWI charges in Union County or anywhere else in New Jersey, contact us now at to discuss your charge with an experienced drunk driving defense attorney who will be able to tell you more about specific defenses that may apply in your case. You can (908) 838-0150 for a free consultation 24/7.