Diabetes and driving

If you’ve got diabetes, you need to be aware of the risks involved when you’re driving. If you know the risks, you can take steps to manage them.

Hypoglycaemia (low blood sugar) 

Low blood sugar levels are dangerous for drivers with diabetes. If you’re taking insulin or tablets for diabetes (except Metformin), it’s very important that you avoid low blood sugar levels, which can dangerously impair your driving.

Hyperglycaemia (high blood sugar)

Very high blood sugar levels could leave you feeling unwell or tired, and may affect your ability to drive safely. You should not drive if you’re severely hyperglycaemic.

Newly diagnosed? 

If your diabetes has just been diagnosed and your treatment is still being adjusted, you may not be fit to drive just yet. Check with your health practitioner, which could be your usual doctor (GP), a registered nurse or nurse practitioner, or a specialist if appropriate.

Precautions while driving 

If your diabetes is well controlled, you can drive a private car safely. However, there are times when you need to take precautions.

1. Always have meals and snacks before and during long journeys. It’s safest not to delay meal times. Take regular, short breaks from driving.
2. Check your blood sugar levels regularly. If you feel that your blood sugar is low, stop driving and treat it with a quick acting sugar, eg three glucose tablets. Follow this up with a plain muesli bar or biscuits. Wait until the sugar has started to work before you start driving again.
3. Keep a supply of plain muesli bars, biscuits, glucose tablets, dried fruit and long lasting fruit juice in your pocket or in the glove box.
4. Don’t delay treating low blood sugar levels. The brain becomes confused when blood sugars reach low levels. Be aware of your warning signs. Although a mild hypo may not seem to impair your driving, it’s vital to act before your judgement is affected.
5. If you sometimes experience hypoglycaemia unawareness (hypos without warning signs), it may be unwise for you to drive. You should discuss this with your health practitioner or specialist diabetes nurse.
6. Remember that changing a car tyre or pushing a car could result in low blood sugar levels. Be prepared!
7. If you have diabetes, alcohol can be particularly dangerous because it can cause hypoglycaemia or worsen its effects. We recommend that people with diabetes avoid consuming even small amounts of alcohol if they’re going to drive.

When you shouldn’t drive

In some situations, you may need to refrain from driving. If you have a mild hypoglycaemic episode, we recommend that you don’t drive for at least an hour, to give your brain time to recover.

If you have a severe hypoglycaemic episode (eg when you need someone else’s help to deal with it), you shouldn’t drive for 24 hours. If you have several hypoglycaemic episodes, you should talk to your health practitioner before you return to driving.

If you have a severe hypoglycaemic episode while you’re driving, you shouldn’t drive for at least a month – whether you’re involved in a crash or not. It’s likely you’ll need to see a specialist before you can safely return to driving, and you’ll need to talk to your health practitioner.

Long-term complications

Your driving ability could be affected by long-term complications of diabetes, such as eyesight deterioration and the loss of normal sensation in your feet. Check with your health practitioner.

Licence conditions

Sometimes a driver with diabetes may be issued with a licence that has certain conditions attached. The conditions will depend on:

• the type of licence (classes and endorsements)
• how the diabetes is controlled
• whether the driver has any history of hypoglycaemic attacks
• how carefully the driver follows their medication schedule
• an assessment of the extent to which the driver suffers from the medical complications that are commonly associated with diabetes.

The Transport Agency decides the licence conditions, having regard to the Medical aspects of fitness to drive booklet, and in consultation with the Transport Agency's Chief Medical Advisor.

Legal note

Insulin and tablets for the control of diabetes are classified as drugs under the Land Transport Act 1998. You may be prosecuted under this act if you misuse or abuse diabetes medications and your driving results in crashes or injuries.

For a case to proceed, however, there would need to be proof that the way you’d used the drugs was contrary to medical advice.

Passenger services and heavy vehicles

People with type 1 diabetes are generally not considered fit to drive heavy trade vehicles, taxis, buses and other related vehicles. The Transport Agency may, in exceptional circumstances, grant a licence after consultation with your health practitioner and diabetes specialist. If a licence is granted to drive any of these vehicles, then strict conditions are likely to be imposed.

Download Factsheet 16: Diabetes and driving [PDF, 52 KB]

Where can I find out more?

• Contact Diabetes New Zealand:
• (04) 499 7145 or 0800 342 238
  www.diabetes.org.nz(external link)
  national@diabetes.org.nz
  
• See your health practitioner or other specialist. A handbook that includes a chapter on diabetes, Medical aspects of fitness to drive, has been issued to all health practitioners.
• Contact the Transport Agency