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Expertspeak: Engineering measures for Forgiving Roads

Expertspeak: Engineering measures for Forgiving Roads

It is only recently that concrete recommendations have been accepted by MORTH for enforcing safety measures. NK Sinha explains what those recommendations are from IRC and IRF, and what the ways forward are.

Road development in India has received a major boost in the last decade through major development programmes of State and Central Governments. National Highways Development Project (NHDP) and the Pradhan Mantri Gram Sadak Yojana (PMGSY) have changed the concept of design and construction technology, particularly with regard to safety. These have become the trend-setter for the roads constructed or under construction from user charges and from funds borrowed from multi-lateral agencies. India is passing through an unprecedented revolution in road development and this is likely to continue for a few decades. Paradoxically, good roads, together with development of vehicle technology, have also unleashed high speeds, and road fatalities have spurted.

India has the highest number of road fatalities in the world. About 10 per cent of 13 lakh people who die each year in road accidents are in India, and a similar proportion of the five crore people worldwide receive serious injuries and disabilities. The growing number of road fatalities may mean that they could become the biggest cause of deaths. The United Nations called for a Global Ministerial Conference on Road Safety in Moscow in November 2009. The Conference urged for vision and urgency for ensuring road safety, and the UN Decade of Action is accordingly being launched worldwide on 11 May this year.

Forgiving roads

There have been debates on which of the factors among the 4Es (see Enforcement through Participation, p 50)–influences road accidents the most. Generally, engineering of roads is believed to have little influence on road accidents, as compared to other causes such as lack of driver competence, user behaviour and enforcement. This belief is, however, fading away. A fresh approach to road engineering is needed in designing and implementing ‘Forgiving Roads’, which would not allow crashes to result in fatalities as far as possible, even if there are some failures of due to lack of driver’s concentration, fault of user behaviour or lack of enforcement.

The concept of Forgiving Roads was developed in the mid-1960s to 1970s when it was recognised that most crashes occur as vehicles hit roadside objects, and that fatalities can be avoided if the distance of the objects from the road edge is suitably increased. Extensive research on the requirements of Forgiving Roads has been carried out in various countries in developed countries since, and have been implemented there. These and other measures for road safety have been able to contain the menace in those countries substantially. Now developed countries are aiming for zero fatalities.

Indian Roads Congress (IRC) has prepared Codes of Practice and Guidelines for design of safe roads, which include geometric design, road surfacing, markings, signs, lighting, plantation, management of traffic and speed, traffic lanes and rules for use of roads and highways. However, these codes, guidelines and specifications do not allow any tolerance that recognises that road users will make mistakes and accidents will occur. That is to say that the concept of Forgiving Roads is not yet included in our IRC codes and guidelines.

Recommedations on engineering measures

4th International Road Federation (IRF) Regional Conference on “Accident Prevention: Road Safety Measures”, held in New Delhi in October 2009 appealed to all stakeholders to stand committed and work collectively to reduce road fatalities. One of the recommendations of the conference was to evolve additional engineering measures to ensure road safety and consequently, reduction of road fatalities. IRF constituted a committee for this purpose. The Committee recommended several engineering measures, in addition to those included in the IRC codes and guidelines, which are considered essential for adoption so as to help in improving road safety leading to reduction of road fatalities. The recommendations are based on the facts that motorists leave the roadway for numerous reasons including errors of judgement and that long term road safety must be ensured even for erring users.

Some of the recommendations of the Committee are mentioned below:

Where land is available, it is preferable to provide wide depressed median having width of 12 m or more, but with W-beam metal crash barriers at the edges of median.

For multi-lane highways with raised median, it is essential to provide:

W-beam metal crash barrier in median along both edges. In case two carriageways are at different levels, median edge of higher carriageway should be provided with a W-beam crash barrier. In case of narrow median of 2 m or less, as generally provided in urban areas, a ‘New Jersey type’ concrete crash barrier should be used along with anti-glare screen.

A lateral distance (width) of at least 1.5 m from the edge of the carriageway should be maintained without any obstacle. Where a permanent object cannot be removed for some reason, provision of fenders and hazard markers with reflectors must be made.

In a constrained situation where deep roadside drains of depth 1 m or more exist, they should be covered by concrete or steel gratings and protected by a W-beam crash barrier. Wherever embankment height is 3 m or more, W-beam crash barrier must be provided at the edge of formation. In greenfield projects of high speed, such as expressways, a slope of 1:4 is required to be provided for ensuring effectiveness of recovery zone, and slopes steeper than 1:4 should be provided with metal crash barriers for safety of traffic.

Local traffic must be separated from through traffic on multi-lane carriageways by adoption of suitably designed service road with safety fence or any other measure. Suitably designed cross connections, such as cattle underpass, pedestrian underpass and vehicular underpass shall be provided to enable traffic to cross over to the other side of the road.

In urbanised sections, appropriately designed footpaths with robust railings shall be provided with cross over facilities like underpass or foot over-bridge.

The crossings of a multi-lane highway with a primary road (National Highway and State Highway) shall always be through grade separator. In case of other category of roads, access to multi-lane highway shall be provided through service roads only.

Wherever a multi-lane highway passes through built up areas, designs should be such to bring down the speed to the level of 60 to 70 kmph with suitable traffic calming measures.

Road Safety Audit should be carried out at all stages, planning, design, construction and operation, for all highways and the recommendations should be duly implemented.

Further research needed

These recommendations have been accepted by MORTH and NHAI, which have issued instructions for their compliance. Engineering measures recommended by IRF would, to a great extent, ensure forgiving roads. However further research is needed to understand behaviour of road users in India under different scenario and in different regions, so that suitable engineering measures to reduce impacts of accidents can be stipulated. Together with other measures like enforcement, education and emergency care, it is expected that these engineering measures will ensure reduction in road fatalities in India.

The author is the Chairman, International Road Federation (IRF), India Chapter, President, Intercontinental Consultant & Technocrats,and Former Director General (Road Development) & Special Secretary, Union Ministry of Road Transport and Highways.

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