I refer to the article entitled ‘Roof gardens and fewer cars in new vision for Valletta’, (The Sunday Times of Malta, September 24).

The article mentions a plan to transform Valletta into a zero-carbon city. If I understood correctly this will be done by replacing one vehicle with another. However, the new system should do away with all types of vehicles. How will people move and circulate in the city? As far as I am aware, all major cities have an underground system.

I would exclude all motorised transport except for electric taxis and other electric official cars. With its hilly structure Valletta is not ideal for pedestrians so a circular underground metro system should be seriously considered. In such a scenario there will be no carbon emissions.

The circular system might start from the Park and Ride Floriana, passing near Belt is-Sebħ, the administrative centre, and on to, perhaps, underneath Old Bakery Street. Near St Elmo it would turn round, continue beneath St Paul’s Street and on to Capuchins Street, out to the parking zone. This should be augmented by bus services with all routes passing through the parking centres.

In Valletta there would be a need for some stations to be serviced by a lift or escalator. The siting of these stations is very important. They would need to be in vital areas, perhaps where there is a small square. With trains travelling every 10 minutes, or more frequently, people would soon get used to such an efficient system.

Ideally we should have an extensive metro system covering all Malta and Gozo, but we need to be practical. We can, and should, start with our capital city.