History of Road and Planning

History of Road :

 

Roman Roads:

The first ever road was constructed in history of road was roman road. In 300 BC roman road was constructed on large scale about 575 km.

The top surface was hard as well as by using different binding material pavement was constructed in different layers but due to the improper drainage system, no cross slopes and large foundation stone proved at bottom layer the failure was happen. 

1. Native earth, leveled and, if necessary, rammed tight.

2. Statumen: stones of a size to fill the hand.

3. Audits: rubble or concrete of broken stones and lime.

4. Nucleus: kernel or bedding of fine cement made of pounded potshards and lime.

5. Dorsum or agger viae: the elliptical surface or crown of the road (media stratae eminentia) made of polygonal blocks of silex (basaltipositionc lava) or rectangular blocks of saxum quadratum (travertine, peperino, or other stone of the country). The upper surface was designed to cast off rain or water like the shell of a tortoise. The lower surfaces of the separate stones, here shown as flat, were sometimes cut to a point or edge in order to grasp the nucleus, or next layer, more firmly.

6. Crepido, margo or semita: raised footway, or sidewalk, on each side of the via.

7. Umbones or edge-stones.

Tresaguet Construction:

After studying the features and drawbacks of roman road side drains as well as cross slope was provided at top layer provided in tresaguet construction.

Tresaguet understood the importance of drainage by providing deep side ditches, but he insisted on building his roads in trenches, so that they could be accessed from the sides, which undermined this principle. Well-maintained surfaces and drains protect the integrity of the sub-base and Tresaguet introduced a system of continuous maintenance, where a road man was allocated a section of road to be kept up to a standard.

Telford Construction:

As compare to tresaguet construction the slight modification was done in telford construction like as cross slope was provided to all layers of pavement but the only drawback was there that large foundation stone was placed at bottom layer.

Mecadam Construction:

Mr. John Mecadam was the first person in 1815 suggested that large foundation stones are not at all required to be placed at bottom layer. 

It is the first method based on scientific thinking. It was realized that the stresses due to wheel load of traffic gets decrease at the lower layers of the pavement and therefore it is not necessary to provide large and strong boulders stones as foundation. Various modern roads are subsequent improvement of this type of constructions.

Sources: Wikipedia