The bridges are now less frequently bnilt of wood; iron or
stone is preferred*).-'
With the great improvements in the construction of the driving-
roads, the cost of mating has of course risen considerably. Road-
making from 1824 to 1854 cost scarcely kr. 10,000 per mile on an
average. From 1860 to 1880, the expenditure for main roads was
21 million kr., which is equal to kr. 22,000 per-mile of increased
length (according to somewhat uncertain estimates). In the years
1880 to 1895, 1,177 miles were constructed for 20 million kr., in
other words at kr. 18,000 per mile. This last decrease is partly due
to. the fact that the newest roads are often narrower, but still
more to technical improvements. The expensive embankments are
largely replaced by jetties; and blasting has become so much less
expensive since the introduction of dynamite; also the implements
are more practical, etc.
I t is a necessary consequence of the natural conditions in
Norway, that the construction of roads must always be comparatively
expensive and difficult. The ice-scratched rock is continually
cropping up and necessitating blasting; and the roads cannot be
made on loose soil as they generally can be in other countries.
The terraces in the valleys, where the road is generally obliged
to wind along the narrow river-bed, often present great difficulties.
The steep declivities from the mountain plateaus to the deep valleys
task the skill of the road-engineers in an especial manner. The
descents from Filefjeld to Lærdal (Vindhellèn, Galderne), from
Dovrefjeld to Drivdalén (Vaarstien), and Stalheim Cliff (1844—45)
on the Yoss and Næreim road, are well known among the old roads.
From later times may be mentioned the precipice from Haukelifjeld
to Raldal, and the way thence across the Seljestad. ravine to Odde
in Hardanger, and the precipitous drop that necessitates great
windings in the road from Lorn (Grjotlien) to Geiranger and to
Stryn (highest points 3,405 ft. and 3,736 ft., descent about 3,500
ft. in about 10 miles horizontal distance).
The three above-mentioned mountain-roads lie so near to the
snow limit, that they are only practicable for wheels during a
very short time of the year (sometimes as little as 2 months). At
*) The longest bridge is across Akersviken (an arm of Lake Mjosen) a t
Hamar, 2,411 ft.; the bridge with the greatest span is across the river Glommen,
a t Rena, 344 ft.