As the Tuscan Apennines divide the peninsula between the Po Valley and the plains and hills of Tuscany and Lazio, transportation over them has been used to achieve political and economic unity. Historically the Romans used the Via Flaminia between Rome and Rimini. The montane distance between Florence in Tuscany and Bologna in Emilia-Romagna is shorter, but exploitation of it required the conquest of more rugged terrain, which was not feasible for the ancients. Railway lines were constructed over the mountains in the early 19th century but they were of low capacity and unimprovable.