Sir John Houlton, the veteran British administrator, who spent many years in the state, describes the Son as follows, "After passing the steep escarpments of the Kaimur range, it flows straight across the plain to the Ganges.

After heavy rain in the hills even this wide bed cannot carry the waters of the Son and disastrous floods in Shahabad, Gaya, and Patna are not uncommon".

[1] When the railway line between Kolkata and Delhi was first laid, it passed through Bhagalpur, Lakhisarai, Patna and Mughalsarai, covering a distance of 1,636 km.

[5][4] The opening of the 4.62 km Vembanad Rail Bridge, connecting the Container Transshipment Terminal on Vallarpadam Island to Edappally, in February 2011, pushed it to the second position.

[7] The Government of Bihar sanctioned in 2008, a bridge across the Son River connecting Arwal and Sahar in Bhojpur district.