Despite the creation of the Swiss Federal Railways in 1902, Switzerland still has a dense private network, with over 40 private rail companies - now mostly run by public authorities - accounting for 13% of the market share of passenger rail transport. They include both standard and narrow gauge lines - with gauges ranging from 600 to 1200 mm. (Standard gauge is 1435 mm. Some 1400 km (870 miles) of the total 5000 km (3110 miles) of today's network is narrow gauge.) Several of them start or end their journeys running along city streets like trams - which is what some of them originally were. They are very accessible, with 1095 stations on their 2,000 km (1240 miles) of track - a rather higher ratio than the SBB which has 740 for 3,000 km (1860 miles).

By far the longest is owned by the Rhaetian Railway in the south eastern canton of Graubünden - it serves the well known resorts of St Moritz, Klosters and Davos, as well as running along the valleys of the Vorderrhein and the Inn, and even over to Tirano, in Italy - a total of 315 km (196 miles).

Several lines compete for the title of the shortest, running only 4 km (2.5 miles). The very shortest is probably Orbe-Chavornay in the southern Jura - which is also the oldest standard gauge electric railway in Switzerland. It was built in 1894.

The original reasons for building the lines have not always survived. Some were conceived as tourist attractions from the very beginning, others served specific local needs. Several were constructed to link disgruntled locals with the main lines which had passed them by. The Bière-Apples-Morges line in the canton de Vaud was built to ferry troops and military equipment to the barracks in Bière; the inhabitants of the Vallée de Joux used their train to transport ice from frozen lakes, which they sold as far away as Paris. The line linking La Chaux-de-Fonds with Ponts-de-Martel, also in western Switzerland, was designed to transport peat, an important fuel at the time of construction.

Most of these lines serve locals or tourists in specific areas, but it might be a surprise to learn that until the introduction of Rail 2000 in December 2004, part of one of Switzerland's main transit lines belonged to the BLS company, and even gave it its name: the Bern-Lötschberg-Simplon, which runs southwards from Lake Thun through the Lötschberg tunnel to the Rhone Valley, linking cantons Bern and Valais on a major route to Milan. Under Rail 2000 BLS exchanged two of its long distance lines and took over some regional lines from the SBB instead.

The example of the BLS shows how being private doesn't mean that companies compete with the Federal Railways. They are supplements, not rivals, and their timetables are worked out to link up with the mainline trains.