The Five Types of Driving Impairment

The Five Types of Driving Impairment

Driver error, mostly driver impairment, causes about 95 percent of the car crashes in California. Impairment-related wrecks are usually not accidental. People accidentally leave the water on. They do not accidentally drive with one eye on the road and one eye on a GPS navigation screen and cause a crash.

Instead, driver impairment usually constitutes negligence, or a lack of care. As a result, a San Jose car accident attorney can obtain substantial compensation for these victims. This compensation normally includes money for medical bills and other economic losses, as well as pain and suffering and other noneconomic losses.


This substance is a depressant which slows motor skills and impairs judgement. This combination of impairments makes it very dangerous to operate a motor vehicle or other heavy machinery.

Alcohol’s impairing effects begin at the first drink. To establish alcohol impairment in court, attorneys usually focus on circumstantial evidence, such as:

  • Erratic driving before the crash,
  • Bloodshot eyes,
  • Unsteady balance,
  • Slurred speech, and
  • Tortfeasor’s (negligent driver’s) departure point.

The burden of proof in civil court is only a preponderance of the evidence (more likely than not). So, if the tortfeasor was at a bar earlier, it is more likely than not that the tortfeasor had something to drink there.

If the tortfeasor violated the DUI law, the tortfeasor might be responsible for the wreck as a matter of law, under the negligence per se doctrine. This rule applies if the tortfeasor violated a safety law, like the DUI law, and that violation substantially caused a crash.


California has one of the broadest DUI drug laws in the country. In 2016, officials charged a Solano man for driving under the influence of caffeine. Especially now that recreational marijuana is legal in the Golden State, weed is the most common culprit in this area. Prescription pain pills, like Oxycontin, are a rather close second.

The impairing effects of many legal and illegal drugs begin with the first puff or pill. My last NyQuil hangover lasted nearly twelve hours. In addition to the aforementioned evidence of impairment, additional circumstantial evidence of drug impairment includes open pill bottles in the vehicle and the tortfeasor’s statements about drug use.

Additionally, thanks to the broad nature of the DUI law, drug-impaired motorists could be liable for damages as a matter of law.


Generally, driver impairment begins well before motorists get behind the wheel. Distraction, which is a form of impairment, is an exception to this rule. Hand-held cell phones get most of the attention in this area. These gadgets combine all three forms of distraction, which are:

  • Cognitive (mind off driving),
  • Visual (eyes off the road), and
  • Manual (hand off the wheel).

Note that hands-free devices are not much better. These devices are cognitively and visually distracting. Other distractions include eating or drinking while driving.

Circumstantial evidence of a lack of care includes erratic driving prior to the crash, a device in the front passenger area, device use logs, and the tortfeasor’s statements about distracted driving. Additionally, California has a hands-free law. So, people who use hand-held phones and cause crashes could be liable for damages as a matter of law.


Many people would never think about driving under the influence of alcohol or drugs. But they have no problem driving home after a long day at the office. In terms of impairment, these things are identical. Driving after eighteen consecutive awake hours is like driving with a .05 BAC level.

Since drowsy driving is not illegal, unless you are a truck driver, operator fatigue usually means the ordinary negligence doctrine and circumstantial evidence. The time of day or night is often important. Most people are naturally drowsy at these times, no matter how much rest they had the night before.

Medical Condition

Many California drivers struggle with chronic medical conditions which could cause a sudden loss of consciousness. Some examples include:

  • Epilepsy,
  • Heart disease,
  • Diabetes,
  • Cancer, and
  • Narcolepsy.

The state normally suspends drivers’ licenses if it receives information about a relevant diagnosis. So, the negligence per se rule could apply in these cases. However, even if the operator’s license was technically valid, it is always negligent to drive in these situations. Medical records normally provide sufficient circumstantial evidence.

Contact a Dedicated Attorney

Impaired drivers often cause serious injuries. For a free consultation with an experienced personal injury attorney in San Jose, contact Solution Now Law Firm. We do not charge upfront legal fees in these matters.


Solution Now Law Firm

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