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Montana driving lesson · Fitness to Drive

Drugs, health and emotions

A 3-minute lesson from the Montana course. Read the rules and examples, follow the handbook page references, and check your understanding before you move on.

Read time
3 minutes
Course unit
Fitness to Drive
Checkpoint questions
6
Source pages
83

Many drugs — prescription and over-the-counter — affect driving like alcohol or worse. Illness and strong emotions can also make you unsafe, so decide each time whether you're fit to drive.

Drugs that can impair driving

  • Medicine for headaches, colds, hay fever or allergies, or to calm nerves, can cause drowsiness
  • Pep pills, “uppers” and diet pills: brief alertness, then nervous, dizzy, unfocused, poor vision
  • Prescription drugs, including medical marijuana, can affect reflexes, judgment, vision, alertness
Handbook p. 83 ↗

Know the rule

Read the label before you drive. A warning about operating heavy machinery means don't drive your car or truck. If unsure, ask your doctor or pharmacist.

Handbook p. 83 ↗

Know the rule

Never drink alcohol while taking other drugs — they can multiply alcohol's effects or add side effects, causing serious health problems or even death.

Handbook p. 83 ↗

Know the rule

Studies show people who use marijuana — even with a prescription — make more mistakes, have slower reflexes, have more trouble with glare, and are arrested for traffic violations more often.

Handbook p. 83 ↗

Know the rule

Even minor problems — a bad cold, stiff neck, cough or sore leg — can affect your driving. If you're not feeling well, let someone else drive.

Handbook p. 83 ↗

Health conditions

Health conditions
ConditionRule
EpilepsyPhysician must certify in writing it has stabilized
Diabetes (insulin)Don't drive if there's any chance of going into shock
Heart disease, high blood pressureIf untreated, shouldn't drive; ask your doctor
Handbook p. 83 ↗

Know the rule

For insulin users, skipping a meal or snack or taking the wrong dose can cause shock. Consider having someone else drive while your dose is being adjusted, and get your eyes checked for night blindness.

Handbook p. 83 ↗

Emotions and stress

  • Stress lowers your concentration on driving
  • Angry or excited: cool off — take a short walk, stay off the road until calm
  • Worried or down: keep your mind on driving; the radio may help
  • Impatient: leave a few minutes early so you won't be tempted to speed
Handbook p. 83 ↗

Put it into practice

You took an allergy pill whose label warns against operating heavy machinery. Treat that as “do not drive” — get a ride or wait until it wears off.

Check your understanding

Read the question, decide on an answer, then open it to check the explanation. These are Roadwise study questions based on the source handbook.

What must a person with epilepsy provide before being allowed to drive?
  1. Nothing extra is required beyond the standard test
  2. A note from a family member
  3. A physician's written note that it's stabilized
  4. A road test passed every year

Answer: A physician's written note that it's stabilized

A physician must attest in writing that the person's epilepsy has stabilized and won't likely interfere with safe driving.

Handbook p. 83 ↗
When should a diabetic who takes insulin avoid driving?
  1. Only when driving at night
  2. Only on trips longer than two hours
  3. Diabetics face no special driving restrictions
  4. Whenever shock risk exists, like a skipped meal

Answer: Whenever shock risk exists, like a skipped meal

Diabetics on insulin should not drive when at risk of insulin shock, such as from a skipped meal or wrong dosage.

Handbook p. 83 ↗
What effect can many over-the-counter cold or allergy medications have on driving?
  1. They can make you drowsy while driving
  2. They have no effect on driving ability
  3. They only matter if taken with alcohol
  4. They make you more alert for hours

Answer: They can make you drowsy while driving

Drugs for colds, hay fever, or allergies can cause drowsiness, which affects your ability to drive safely.

Handbook p. 83 ↗
What does a drug warning label about 'operating heavy machinery' mean for drivers?
  1. It only applies to construction workers
  2. Don't drive after taking it
  3. You may drive if you feel fine
  4. It only matters for commercial drivers

Answer: Don't drive after taking it

A warning about heavy machinery applies to your car or truck too; it means do not drive after taking that medication.

Handbook p. 83 ↗
According to studies cited in the handbook, how does marijuana use, even with a prescription, affect drivers?
  1. It has no measurable effect on driving performance
  2. It improves reaction time
  3. More mistakes, slower reflexes, more arrests
  4. It only affects new drivers

Answer: More mistakes, slower reflexes, more arrests

Studies show marijuana users make more mistakes, have slower reflexes, struggle with glare, and get more traffic arrests.

Handbook p. 83 ↗
What should you do if you're feeling angry or excited before driving?
  1. Take a walk and wait to calm down
  2. Drive faster to work off the emotion
  3. Turn off the radio and drive silently
  4. Ignore it, since it doesn't affect driving

Answer: Take a walk and wait to calm down

If angry or excited, take a short walk or otherwise cool off before getting behind the wheel.

Handbook p. 83 ↗
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