Below are useful links providing information for health professionals:

Medical aspects of fitness to drive. A guide for medical practitioners

http://www.nzta.govt.nz/resources/medical-aspects/1.html

Information for Elderly Drivers

http://www.nzta.govt.nz/resources/factsheets/57/older-drivers-licence-renewal.html

http://www.ageconcern.org.nz

New Zealand Transport Authority

https://www.nzta.govt.nz/assets/resources/factsheets/51/docs/51-ot-assessments.pdf