The study aim was to gain a better understanding of the characteristics of informal caregivers who provide transportation assistance and to explore the types and frequency of this assistance. A telephone survey was administered to a representative sample of 268 informal caregivers (age 45-80) who provide transportation assistance to older adults (age 70 and older) in Michigan. Responses were analyzed overall and by the caregiver sex and care recipient age. Informal transportation caregivers were: most often women; on average 61 years old; generally college educated; employed full- or part-time jobs; relatively healthy; providing care to a parent/family member 1-4 times per week, living close to the care recipient; and providing assistance by giving rides. Less than one-half of caregivers sought information to help them provide assistance. No significant burden was reported and there were few differences by sex of the caregiver of the age group of the care recipient.