INE publishes the first statistical data on the transport and communications activity in 2000.
It contains some relevant aspects, such as:
Instituto Nacional de Estatística - Estatísticas dos Transportes e Comunicações : 2000. Lisboa : INE, 2002. Available at www: <url:https://www.ine.pt/xurl/pub/130139>. ISSN 0377-2292. ISBN 972-673-549-1