Short term memory and visual tracking were impaired. A history of heart failure or heart attacks was a weaker predictor of bad driving skills. In Finland, many elderly drivers who were refused car licenses switched to mopeds, bicycles or walking with accident fatality rates in the elderly that were more than twice that in Sweden. Physicians are often confused as to how to assess driving ability. Statutory requirements for getting and renewing a drivers license vary from state to state and keep changing.
Mental function screening, however, is expensive.
Control of diseases such as glaucoma and diabetes, and more exercise has improved the ability of elderly drivers. Human error is the main factor in two thirds of accidents. Alcohol and some types of medicine such as Valium or antihistamines affect driving ability. There is a clear relationship between mild dementia, driving score and collision or moving violation frequency. Elderly drivers are experienced individuals who rarely drive without a license, speed, drink or disregard the traffic laws.