Concrete roads have a large number of advantages over bituminious ones. These advantages include:

• Fuel Saving:Concrete roads are rigid pavements, which do not deflect under loaded trucks, unlike bitumen pavements. Hence load carriers require less energy when travelling on concrete roads (since no effort is expended in getting out of deflection 'ruts'). Trials carried out in the USA by the Federal Highway Administration and in India by the Central Road Research Institute, have shown that laden goods carriers consume 15-20% less fuel on concrete roads as compared to bituminious ones. Considering the fact that about 60% of our country's goods traffic moves by road, construction of a nation-wide network of concrete roads could thus save us hundreds of crores of rupees worth of foreign exchange now being spent on importing petroleum products.

• Long Maintenance-Free Life:Concrete roads have a life of 40 years or more, compared to 10 years for bituminious ones. In addition, concrete roads require almost no maintenance, whereas bituminious ones need frequent repairs due to damage by traffic, weather, etc.

• Gain in Traffic Speed:Concretising of existing roads in Mumbai, Nagpur, Calcutta and other cities has shown that this leads to significant gains in traffic speeds, making in turn for a notable reduction in congestion and jams on high traffic density roads. This increase in speed of vehicular movement , is due to the smooth concrete road surface which neither needs repairs, nor allows digging can be dug up for laying utilities (for which ducts provided in advance below the road surface). Increased traffic flow means saving of both time and fuel, as well as reduction of pollution caused by idling engines.

• Resistance to Weather, Oil Spils, etc.: Concrete roads are neither damaged by rain (being waterproof), nor softened and distorted by heat. They also do not lose their binder due to leakage of oil from vehicles. Hence they remain damagefree under most adverse conditions.

• Economy in use of materials:For the same traffic load conditions, concrete pavements are thinner than bituminious ones. Where the load bearing capacity of the soil is poor, a bituminious pavements may have to be made more than one-and-a-half times thicker than a concrete one. Concrete roads thus use less aggregates, which are in short supply or difficult to procure in many places.

• Enviormental Friendliness:Concrete roads score over bitumen ones, as far as enviornmental friendliness is concerned, in several ways. Firstly, production of concrete does not foul the atmosphere like the hot-mix bitumen-based plants (the latter have been banned from operating in some cities, due to their polluting nature). Secondly, concrete pavements can utilise fly ash, a polluting byproduct of thermal power plants. Addition of fly ash to concrete increases its density as well as its resistance to chemical attack. Finally, as already mentioned, faster movement of vehicles on concrete roads leads to lower pollution from vehicular emissions.

• Use of Indigenous Materials:Concrete roads use cement, which is manufactured from indegenously available materials like limestone, of which a plentiful supply is available. Bituminious roads need bitumen, which is obtained from imported crude oil (since Indian crude contains almost no bitumen). Besides which, availability of crude oil both in India and abroad is likely to reduce in the near future , thus jeopardising bitumen supplies required to repair existing bituminious roads.

• Other Advantages:These include better reflectivity due to lighter colour(hence greater safety and lower lighting requirements), greater skid resistance and so on.

Concrete roads, however, have one disadvantage vis-a-vas bituminious ones, in that they are initially costlier to construct. However, with the price of bitumen going up steadily, and the use of fly ash (available free from power plants) in making concrete mixes for pavements now being accepted, the relative cost of these two types of pavements could become quite comparable.

When life-cycle costs are considered (as recomended by the BIS, for all competing technologies), concrete pavements with their long life and negligible maintenance, come out invariably superior to bituminious ones.

As regards the economic costs to the country, fuel saving and enviornmental friendliness make concrete roads a far superior choice over bituminous ones.