This proposal assumes construction of the Šaľa – Nitra rail line. That link would allow trains from Bratislava to enter Nitra from the south, over a shorter route (about 85 km), via the Bratislava – Budapest line.
Via a new tunnel in Nitra, and a new line eastwards, they could reach the existing line along the Hron valley – the line to Zvolen. It is possible for trains to do that already, but the route is indirect and inconvenient. The existing line runs in the ‘wrong direction’ at first, and then over the Tribeč mountains, passing north of Mount Zobor to Jelenec. From there, the existing line passes through Zlaté Moravce, and joins the Hron valley line at Kozárovce. In general the existing route follows the edge of the mountains. Most of the new alignment would be somewhat further south, but it would join the Hron valley line at Psiare, 2 km north of Kozárovce.
The first requirement is a new eastern exit from Nitra. Since it would be used by trains coming from the south, it would logically run north from Nitra station, and then east. That is only possible with a tunnel, of about 3 km. This option would allow a new station in eastern Nitra, and possibly under the city centre as well. With 85 000 inhabitants, Nitra is large enough to justify extra stations. Two possible alignments are shown. The southern option (blue) would enter tunnel just before Nitra station, with underground platforms alongside the existing station.
The new line would then parallel the main road out of city to east, Zlatomoravecka cesta. It would parallel this road for 14 km to Jelenec, where it would join the existing rail alignment (line to Zlaté Moravce). Probably, a short tunnel under ridge at Kolíňany would be necessary.
Passing Jelenec, the new line can follow the existing straight alignment. It would then run parallel to the existing line, rejoining it at Choča. From Choča, trains could use the existing line to Zlaté Moravce station. (The town has 13 000 inhabitants, the Zlaté Moravce district 43 000). The new line would diverge at Choča, south-eastwards toward Kozárovce. The alignment shown is only schematic, but the geography implies a route north of Tesárske Mlyňany, south of Volkovce, and north of Kozárovce. The alignment shown crosses several ridges and valleys: the ridges are 30-50 m higher than the stream in the valley. Some viaducts and short tunnels may be necessary.
North of Kozárovce the line would split. The south fork would turn into the existing Kozárovce station. Trains would continue over the relatively straight and level line to Levice. This town has 35 000 inhabitants, and is capital of the Levice district (118 000).
The north fork would join the Hron valley line at Psiare, where the valley narrows before passing through the mountains. The line in the valley must be upgraded, as part of the total route to Zvolen, but that is not considered further here. On the image, the corridor along the Hron valley is clearly visible, with the basin around Žiar_nad_Hronom. The larger town of Zvolen (population 43 000) is 20 km further.
The total length of the new alignment from Nitra station to Psiare, would be about 42-44 km. It would improve inter-regional services from Nitra to 4 other district capitals (Zlaté Moravce , Levice, and Zvolen).