Saturation system
In this system the optimum road length is calculated for area, based on the concept of obtaining maximum utility per unit length of road. Hence this system is called saturation
system or maximum utility system. The factors which are taken for obtaining the utility
per unit length of road are
(a) Population served by the road network
(b) Productivity served by the net work
i) Agricultural products
ii) Industrial products
The following steps may be followed to find the road net work having maximum utility
per unit length by the saturation system.
Step (i) Population units. Since the area under consideration may consist of villages and towns with different populations, it is required to group these into some convenient population ranges and to assign some reasonable values of utility units to each range of
populations served. For example, villages having population range between 1001 and 2000 may be grouped together and be assigned one utility unit per village. Similarly the various villages and towns may be grouped in different population ranges and be assigned
Suitable utility units
Step (ii) Productivity units. The total agricultural and industrial products served by each road system should be worked out. The productivity served may be assigned agricultural products may be considered equivalent to one unit. Similarly the industrial products may also be assigned some suitable utility units per unit weight.However, coal, raw materials like ores etc. may be assigned lower utility values than the industrial products. From plan II showing the products in the area, the total productivity units appropriate values or utility units per unit weight. For example one thousand tonnes of served by each road system may be estimated.
Step (iii) Utility. The total utility units of each road system is found by adding the
population units and productivity units. The total units are divided by the total road
length of each system to obtain the utility rate per unit length.
Each road system having different layout and length would show different values of utility per unit length. The proposal which gives maximum utility per unit length may be chosen as the final layout with optimum road length, based on maximum utility on the saturation system. This method is useful not only to choose the best layout from the alternate proposals,
but also to phase the road development plan. The only limitation of thè system is the
possible variation in the relative weightages assigned to population and productivity. It is possible to give a relatively higher weightage either to the population or to a certain type of products. A sound judgment based on professional skill and experience should be helpful in providing balanced weightages for arriving at the optimum road length or the best road system with maximum utility per unit length of road.
Phasing of Road Programme
The road net-work to be constructed and improved in the plan period is decided while finalising the master plan of the road development project. The plan period may be of ablong term, like that of the 20-year road plan or of shorter period like five year plans. But whatever be the plan period, it 1s necessary to phase the road development programme from financial considerations. In other words, it is necessary to fix up the priorities for
the construction of each link of the road net work development programme to decide which link should be taken up first and which one the next and so on. The phasing may also be done for each annual budget year by fixing up the priorities.
Here again the priority for each road link may be fixed scientifically based on
maximum utility. The utility per unit length of road based on population and productivity for each road is worked out. Then each link or the net work 1S listed in the order of priority based on utility per unit length of the road.
