The construction of transport infrastructure has been vital to maintain the economic position of Madrid. Travel to work and other local journeys use a high-capacity metropolitan road network and a well-used public transport system. In terms of longer-distance transport, Madrid is the central node of the system of ''autovías'' and of the high-speed rail network (AVE), which has brought major cities such as Seville and Barcelona within 2.5 hours travel time. Also important to the city's economy is Madrid-Barajas Airport, the fourth largest airport in Europe. Madrid's central location makes it a major logistical base.