Mr Cheng Choon Fei's point that the skills needed to drive safely diminish with age is well understood (Seniors should retake driving test to renew licences, June 18).

His concern for keeping Singapore roads safe by testing driving skills beyond a certain age is appreciated.

However, his conclusion that the appropriate age for testing is 65, based on statistics showing that drivers who are 60 years and older accounted for 11.6 per cent of total casualties in 2009, rising to 15.6 per cent in 2012, is questionable.

There are too many unanswered questions, such as what the percentage of total drivers who were 60 years and older was in those years, to come to an arbitrary conclusion.

While Mr Cheng's intentions are good, we need a deeper understanding of the situation to ensure that we arrive at the best decision.

Choo Hock Lye