Mixed trains were once prolific in
New Zealand. Although
express trains operated on the main lines, mixed trains served rural branch lines where dedicated passenger services would be uneconomical. On the more significant provincial routes, substituting a mixed train during the off-season was common in the late 19th century (the
Rotorua Express), or operating the provincial express twice or thrice weekly while mixed services ran daily (the
Taneatua Express). The shortcomings of mixed trains for passenger travel led the
New Zealand Railways Department to investigate railcar technology in the early 20th century. Overseas designs could not be easily adapted to New Zealand owing to its rugged conditions,
narrow gauge track, and small
loading gauge. Early railcars trials, such as the
RM class Model T Ford railbuses, proved unsatisfactory. When successfully introduced from the 1930s, railcars primarily replaced unprofitable provincial carriage trains, and some mixed services in regions such as the
West Coast and
Taranaki. Mixed trains dominated the
South Island's more extensive branch-line network, but as private car ownership increased in the 1930s, passenger traffic decreased, closing many rural train routes. However, some mixed services lasted into the 1960s in isolated regions with poor roads. In the
North Island, the last mixed trains operated into the 1970s, where services on the
North Auckland Line ran until 1976. An updated type of mixed train existed in the South Island for a few years during the 1990s, when a few wagons of express containerised freight were attached to the
TranzCoastal Picton–
Christchurch express. Unlike prior era mixed trains, with their slow en route shunting, this time-sensitive freight travelled swiftly. ==North America==