Raxaul

Has both meter guage and broad gauge network. It is a major town but not the focal point of the local services.

Gorakhpur is the most influential major center.

Raxaul lies to the east along one of the paths north of the Ganges converging again at Katihar

about a dozen Meter gauge trains run each way between Narkatiagani and Darbhanga.

Other routes from Gorakhupur – Narkatiagani & around Samastipur have either been converted or are being converted to broad guage.

Its important as the meter gauge trains on the Narkatiagani to Darbhanga cover 192km in 8hours, about 25km/h

where as the fewer broad gauge trains from Narkatiagani to Samastipur cover 210km in 4.5hours

next stop Calcutta

There are 2 ways that I can see to make the trip. You can take the direct daily Mithila Express,

take the 0600 meter gauge to Darbhanga (a1330) then at 1445 the Mithilanchal Express

take a train to Muzaffarpur Junction then on the Bagh Express to Howrath Junction.

There are a couple of other routes too, after checking it appears that the Bagh express has much better availability than the Mithila. eg: sleeper class still has availablility for tomorrows dep, the Mithila has a Wait List for all classes for the next 8 days.

This is likely due to the tourist factor and border crossings. It also keeps much better time, at least over the last month.