IT was good to see the initiative shown by so many young people on Friday demanding more environmentally friendly policies to help prevent disastrous climate change ("Children of the revolution in protests over climate crisis", The Herald, February 16). It is also good to see that there will be a debate in the Scottish Parliament on Thursday entitled Delivering Sustainable and Renewable Transportation for Scotland.

This emphasises Parliament’s responsibility to act and talks about ultra-low emission vehicles and the use of hydrogen technology for rail and marine vehicles to deliver a “truly sustainable transport network…for future generations”. As Nicola Sturgeon commented “it is right that we are all challenged to do more and that we hear the voice of the next generation”.

Rail is seen as one of the more environmentally sustainable transport modes for both passengers and freight, but to play its part it needs to have adequate tracks and terminals. Your correspondent Dave Stewart brilliantly outlined the problems of having more demand than the seriously restrictive single track line to Milngavie can cope with and how this has had a deleterious effect on punctuality across the central belt (Letters, February 14). Another strategic line where single tracking has become a serious constraint is the Highland Main Line from Perth to Inverness and its meandering connection from Edinburgh.

It seems to me that, after a good start with the 2008 Strategic Transport Projects Review, the Scottish Government lost momentum in 2010 when the Climate Change portfolio was taken away from the Transport Minister. This uncoupling seems to have caused sight to be lost to the fact that transport emissions have been rising year on year and are still rising. All the publicity displays a kind of tunnel vision highlighting only the other areas of the economy where there have been very welcome emissions savings.

Meanwhile, the 2008 promise to create an average rail journey time of three hours between Edinburgh and Inverness by 2012 recedes with the average journey time actually increasing from 3 hours 28 minutes in 2008 to 3 hours 40 minutes from December 2018. The extra frequency of passenger trains in recent years is greatly to be welcomed but the requests from freight trains operators for more capacity are seemingly unheeded. The single-track lines to Milngavie and Inverness have got to the point where they cannot be expected to operate efficiently because they have reached full capacity. Single-track lines between our cities are supposed to become history, but when will this happen? Some effective strategic and environmental action is urgently required.

R J Ardern,

Drumdevan Road, Inverness.