Oberaargau-Jura Railways

The Oberaargau-Jura-Bahnen (OJB) (Melchnau-Langenthal-Niederbipp) based in Langenthal was formed in 1958 from the merger of the Langenthal-Jura-Bahn (LJB) and the Langenthal-Melchnau-Bahn (LMB). As a result, the OJB is the direct legal successor of the LJB, which was opened in 1907 and, after the opening of the LMB in 1917, was also responsible for its operational management.

The metre-gauge lines of the predecessor companies became part of the company's assets, including the almost 11 km-long Langenthal–Aarwangen–Niederbipp line of the LJB and the more than 11 km-long Gaswerk–St. Urban–Melchnau line of the LMB. The two railways, most of which are located in the canton of Bern have been electrified at 1200 Volt DC since their opening.

As a result of the merger, cooperation with the SNB was renewed in 1959 under a new operating contract. The workshop built in Langenthal by LJB also became a workshop for the SNB rolling stock. The two companies also made their new rolling stock purchases together.

Due to the sparse settlement along the LMB line, which primarily served businesses established along the line, and the long route to Melchnau as a result of the long eastward sweeping curve it followed, passenger traffic on the St. Urban–Melchnau section was abandoned on 22 May 1982. The section remained open for goods traffic. Passenger services to Melchnau were replaced by buses, which allowed a significant reduction of travel time as they used a more direct route to Langenthal.

An early sign of the later merger was a formal agreement that was contracted on 5 April 1984 between the BTI, the OJB, the SNB, the Oberaargauischen Automobilkurse (a bus company; OAK), the Ligerz-Tessenberg-Bahn (a funicular railway; LTB) and the Bielersee-Schiffahrts-Gesellschaft (Lake Biel Ferry Company; BSG) to form Oberaargau-Solothurn-Seeland-Transport (OSST).

Construction activity in St. Urban led to a small increase in passenger numbers, which allowed the section of the LMB line between St. Urban and St. Urban Ziegelei to be reactivated for passenger traffic on 28 May 1989.

The OSST partners, BTI, RVO, SNB and OAK, were merged into Aare Seeland mobil (ASm) in 1999. The LTB was also merged into the ASm in 2003, while the BSG continues to be legally independent.

The ASm route has been extended from Niederbipp to Oensingen, with the line running largely parallel to the existing SBB route. It was opened at the timetable change in December 2012. A tramway existed on this route under the LJB from 1907 to 1943 and it was occasionally used by the SNB.