Via Flaminia was built by Gaius Flaminius about in 220 B.C. to connect Rome with Ager Gallicus. Via Flaminia represented a basic element for Roman expansion project in this territory and it was a route of fundamental importance linking Rome with northern Italy and later with central and eastern Europe. Flaminia route followed ancient prehistoric paths ( sometimes tratturi)  and it was realized using rectilinear stretches linked by bridges, viaducts, tunnels and substructures (sostruzioni) . Via Flaminia started from Rome, followed the Tiber valley up to the Apennines, crossing the mountains in Scheggia Pass and the Metauro valley, passed by Fano (Fanum Fortunae) and Pesaro (Pisaurum), coasting the Adriatic sea up to Rimini (Ariminum)
Costruction date of via Flaminia
The construction of via Flaminia is attributed to Gaius Flaminius, refering to the literary and historical sources, for example Cassiodoro (Cron. a.u.c. 534). However the exact construction date of via Flaminia is still in dispute, for the different informations coming from sources, that waver between  220 or 223 B.C. In fact,  according to some ancient authors, via Flaminia was built by Gaius Flaminius when he was consul in 223 BC (Paolo Festo 79, 16 L)   and for others was built during his censorship in 220 BC. (Livio, Perich., Epitome XX). About this question, there is a long discussion among  modern authors, because of legal and administrative reasons, first of all for the public position of Gaius Flaminius,  even if the more accepted is the ipothesis of  220 B.C.
Ager Gallicus
Ager Gallicus was the territory taken away by Rome to Galli Senoni at the beginning of III century B.C. after the Sentinum battle (295 B.C.) and made part of roman property. Nowadays this territory corresponds  to northen part of Esino river in Marche Region. The Roman, in order to control the ager, deducted, on the coast, the roman colonies& of Sena Gallica (Senigallia, founded about in 284 B.C. as colonia civium Romanorum), Ariminum (Rimini), Pisaurum (Pesaro) and Fanum Fortunae (Fano). In 232 B.C. Lex Flaminia de agro Gallico et Piceno viritim dividundo (Gaius Flaminius Act about Picenus and Gallicus territory division) organized the administration of the countryside, creating a net of praefecturae that since half the  first century BC assumed the dignity of municipia, as Aesis (Jesi), Suasa, Ostra, Forum Sempronii (Fossombrone). Ager Gallicus, after the augustean administrative reorganization of Italic peninsula, enters to make part of Regio VI, called Umbria et Ager Gallicus. Via Flaminia represented in this point of view an ulterior element of unification between the Umbrian and the Gallici in a one Regio.
Regio
The regions were not intermediate organs between the central government and cities and have not political or administrative functions.  At the beginning of the roman empire Italy was a whole of territories with various statuses:  the cities were municipia, which had independence and political-administrative autonomy, and coloniae, cities of new foundation that the Roman had created in order to control an unstable frontier territory. Augustus grouped these cities with ethnic and geographic criteria also in order to carry out the censuses for immense but enough homogenous areas . Plinius Senior reported in  Naturalis Historia (III 46), that  Augustus reorganized the Italian peninsula, subdividing it in the following regions:     Regio I Latium et Campania Regio II Apulia et Calabria Regio III Lucania et Brutii Regio IV Samnium Regio V Picenum Regio VI Umbria et ager Gallicus Regio VII Etruria Regio VIII Aemilia Regio IX Liguria Regio X Venetia et Histria Regio XI Transpadana