Sir – The two main bus companies serving Oxford continually remind us just how efficient their low-carbon-burning engines are proving.

I suggest they could make more drastic reductions if they simply reduced the frequency of buses at low demand times.

Last Saturday, my wife and I sat in the window of a Summertown restaurant, directly opposite the bus stop, and counted 17 southbound buses (a mixture of number twos and sevens) in less than an hour.

Most of them had less than half a dozen passengers. Why do we need a bus every 3.5 minutes on a Saturday afternoon? I have not monitored the frequency on week days but I suspect it is similar.

Tom Williams Oxford