Before the opening of the Vereina tunnel in 1999 the Chur-Arosa line was the last major addition to the narrow gauge network in the Grisons. The modern construction of large ferro-concrete viaducts and the use of relatively high voltage DC catenary system prove this point.
Many different projects for similar lines existed before the construction of this railway line began. One of them was for example a cog-wheel railway that would have negotiated the first ascent from Chur to the valley of the Plessur river. Instead the route now follows the streets of the upper part of the town. In spite of the fact that the Chur-Arosa railway was founded as an independent company (ChA) its network had always been linked to the Main Network of the RhB in Chur. This link enables the exchange of passenger coaches and freight cars. The merger with the RhB was the beginning of the modernisation of the ChA railway. State-of-the-art remote controlled signal boxes and shuttle trains characterise the Chur-Arosa line. Especially in winter this line has to cope with extraordinary heavy weekend traffic.
The power supply was changed from 2400 V DC to 11 kV AC in 1997. Today the motor cars of the Chur-Arosa line have all been decommissioned - some were sold to other railways. Locomotives of class Ge 4/4 II are mainly used to haul the shuttle trains of this line now. Locomotives of class Ge 4/4 I can be seen on this line on rare occasions as well. A special attraction of the Chur-Arosa line is the Arosa-Express. An entire shuttle train (except the locomotive) was fitted with a fashionable blue design and a comfortable interior. A first class coach features extra large windows and an extraordinary seating arrangement.