During the first half of the Meiji Era, the raw silk industry developed in Naganoand the newly wheeled vehicles such as horse carriages increased gradually. To accommodate such wheeledvehicle traffic, the construction of new main roads were proposed., namely the construction plan of the seven new main highway lines were started in 1882 and the construction of another four main highways were started form 1888.
At that time these were most important large scale undertaking in the road administration of Nagano prefecture in Meiji Era. The various documents including route survey maps, drawings of bridges and specifications were made before construction works started. The private enterprise contracted to construct these works by competitive bidding.
In addition to this, the technical report of De Reijke on roads and bridges affected these construction works.
As new highway roads were constructed, the traffic density of horse carriages increased largely and the raw silk industry developed rapidly. There is a close connection between these two events.
