Cádiz tram-train testing underway
https://www.railwaygazette.com/urban-transport-news-from-metro-report-international/cadiz-tram-train-testing-underway/56025.article
One of the biggest weak points of tram systems would be slower speed. So, in order to minimize its weakness and remove troublesome transferring, it would be effective to make trams run through suburban rails.
