The focus will be to rehabilitate flexible, or asphalt, pavement which constitutes the most important and largest component of the ageing national highway network. The ministry of road transport and highways has sought comments on a draft policy that lays down the technique, its benefits and the selection criteria for identification of national highways to be rehabilitated.
India currently has a national highway network of about 146,000 kilometres. “As India is building more and more two-, four- and six-lane national highways and expressways, the quantum of aged assets is increasing which warrants rehabilitation to extend its life further,” a senior government official told ET.
Though there are several techniques and treatments available to strengthen flexible pavement, India has opted for the thin white-topping technique, the official said. In white topping, a concrete overlay is constructed on the top of an existing in-service bituminous pavement. In thin white topping, the thickness of the concrete is 100-200 mm. The technique is extensively deployed in developed nations but is yet to be taken up on a big scale in India.
According to the official, this is expected to extend the lifespan of the pavement by 20-25 years, has lower life-cycle costs when compared with bituminous overlay, is durable and requires much less disruption during the process.
Also, fuel consumption of vehicles travelling on concrete roads is less than the bituminous roads and hence can lead to saving on fuel and a reduction in carbon emission. Besides, concrete is relatively light in colour and hence more reflective to light, absorbs less heat and reduces the urban heat island effect. Improved reflection of lights from vehicles enhances safety, lowers energy requirement of external lighting, the official added.
The ministry recently directed the National Highways Authority of India (NHAI) to focus on upgrading existing national highways, amid rising maintenance concerns. As per the directive, the NHAI will undertake 79 national highways (original) projects spanning about 1,421 km at an estimated cost of ₹1,44,392 crore in this financial year. Of the ₹1,44,392 crore, ₹71,112 crore is to be spent on NHO1 projects and ₹73,280 crore on NHO2 projects.
NHO1 projects involve maintenance, repair and minor upgrades of the original national highways, while NHO2 projects often include more extensive upgrades and modernisation of the original national highways, aimed at enhancing the capacity and safety of the highways, accommodating increased traffic and improving overall efficiency.
