Crash barriers, Yes. Implementation, Difficult

TrafficInfraTech spoke to barrier providers during the Smart Mobility Expo, Mumbai in September and also very recently after the Eastern freeway accident to find out what they felt about the challenges in implementation of performance and quality standards for crash barriers in India.

VRK Eshwaran, Managing Director, Hill & Smith Infrastructure India Pvt Ltd, said, “To improve the road safety in the country, the Ministry had migrated its road safety standards, particularly for road crash barriers, from ‘material-based standards’ to ‘performance-based standards’ in 2015. (Reference is made to IRC 119.) However, the same is yet to find implementation in the project and on ground. Even in the newer projects the new standards are not being implemented.”

There are basically three types of barriers that are available in the market and in use globally:

• Rigid barrier, which is made of concrete and provides highest level containment;
• Semi-Rigid barrier, which is made of metal (steel) and has a lower level containment. Currently, barriers that are installed in Indian roads are NOT crash tested products;
• Flexible barrier, which is made of wire rope and has low level containment.

“Depending upon the road conditions and containment levels required, the engineer a n d authorities decide which type of barrier to be installed/ used in such locations. For example, where you need highest level containment, like bridges and ROBs, you will use concrete barriers. But where you need medium to low level containment, depending upon the site conditions and working width available, you will use either semi-rigid barrier or wire rope barrier.

“However, recently, a new type of barrier – roller type barrier – which has been introduced, can be used in locations like the accident spot in the Eastern Freeway. When impacted, the wire rope barrier being flexible, redirects the vehicle safely on its travel way causing minimum damage to the vehicle and injury to the occupants.

“The authorities could also consider using used tyres in such black spots as a cost effective solution, and this is also used in the F-1 tracks to mitigate fatalities in case of a crash. Wire rope barriers are ideal for high speed corridors like expressways, where you have sufficient width available behind the barrier to allow the designed and tested deflection of the system.”

Bharat Anand, Safety First, felt that the impact severity of the Freeway accident could have been drastically reduced by using a tested bridge parapet system at the accident site. The European Norms for Crash Test Approval for Systems (EN- 1317) takes into account the following three criteria to approve systems:

1. Containment Level (tests the Weight and Speed of Vehicle for the said safety barrier).
2. Working Width (Maximum deflection when a vehicle impacts the barrier).
3. Impact Severity (ASI of Class A to Class C with Class A being least severe).

“Unfortunately in India, Tested Systems are being implemented in very few locations and in most scenarios none of the above is being considered. The common practice is to put the most rigid system that money would allow.

“Developed nations have in the past used extremely rigid barriers, but over the past decade, rigid barriers are used only in extreme conditions. The trend is very clearly moving to flexible and semi-flexible barriers. The authorities have realised that more than 80% of accidents happen due to human errors, but the buck does not stop at whose fault it is but how the roads and safety installations handle the inhabitants of the crashing vehicle when an error has occurred. Great efforts are made to install the most flexible system that the site conditions would allow – in fact, all crash approved systems including Metal Beam, Wire Rope and Bridge Parapets in the developed world are flexible and have an Impact Severity of ASI Class A or B except to Concrete Barrier where it is Class C.”

Coming back to the particular site of the accident, Bharat opined that it would fall in the high risk category, as it is a flyover on an Expressway and thus, it would not be suitable to install Metal Beam or Wire Rope Crash Barriers but a tested Bridge Parapet would have been suitable. These Bridge Parapets are tested to highest containment levels (36 tonne vehicles) and have a low deflection as well as acceptable impact severity (i.e. Class A or B).