I applaud Max Lazarus' support for trolley buses (Letters, 17 September) and agree with all he says about trams.
Until 1949 I lived near the longest trolley route in the UK, Nottingham to Ripley, which worked well and provided a much-needed, reliable service.
In Cambridge the authorities have been disrupting all transport to construct a guided busway to travel along a disused railway line.
This is utter madness as no-one seems to count the cost of the disruption and disaffection caused, which all too often results in people turning their backs on public transport altogether.
J Gray, Warks
Wheels of misfortune

Simulations show Optimal Design for Bladeless Wind Turbines
"an 80cm mast" Really? I'm short but that's only half my height! Do they mean 800cm?