The Iowa Transit

The Iowa Transit

4.11 - 1251 ratings - Source

Subsurface or under drainage provides for the removal of water from the subgrades and the intercepting of the ground water from ... Water in the subgrade makes it soft and yielding and a satisfactory surface cannot be maintained on a soft foundation. ... The greater proportion of our rural highways will consist of earth roads for a long time in the future but the main highways are being ... About one half of all money spent on road construction and repairs is spent for bridges and culverts.

Title:The Iowa Transit
Publisher: - 1917


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