Roads designed for safety
After my visit to Malta in 2011, it was with sadness that I recently read the report of a young priest killed on the Tal-Barrani Road. This is probably one of Malta’s most dangerous roads. With more than 25 years of experience in road safety, I must express my concern regarding the need for the authorities to take action. Together with planning and maintenance of infrastructure comes the responsibility for road safety.
A significant element of a successful road safety strategy is to ensure that roads and roadsides are of a high standard and that the risk of crashes is minimised.
The aim of the design must be to provide a roadside that is forgiving in the event of a crash. Sweden is as a good example of how this can be addressed.
Vision Zero is the Swedish approach to road safety thinking. It can be summarised in one sentence: No loss of life is acceptable.
The Vision Zero approach has proven highly successful. It is based on the simple fact that we are human and make mistakes. The road system needs to keep us moving. But it must also be designed to protect us. The key factors are:
* Freedom to move. Mobility is crucial for all parts of society. But more traffic means more fatalities and injuries on the roads.
* The human factor. Humans are not made to travel at high speed. We make mistakes. Thus, an effective road safety system must always take human fallibility into account.
* Responsibility. Transport systems traditionally place responsibility for safety on road users. The Vision Zero Initiative puts this responsibility on system design.
Does it work?
The Vision Zero approach to road safety is highly effective. Sweden has one of the world’s lowest traffic-related fatality rates – and the statistics clearly show that safety does not compromise mobility. On the contrary, increased mobility actually depends on effective road safety.
It takes a combination of the three Es to achieve this: Education, Engineering and Enforcement. My personal experience tells me that the engineering and design of the roads play a crucial part in this concept. During my visit to Malta I had several meetings, including with Transport Malta, during which we discussed the solutions that are available.
It has been proven worldwide that the use of crash barriers in combination with energy absorbing end treatments and crash cushions is a very cost-effective solution to most “problems”. Because it is a problem if a young priest loses control over his car and crosses over the median strip to collide with two other vehicles. He is not only jeopardising his own life but also those of other road users. Cross-over accidents are one of the fastest growing types of accident worldwide and the result is often devastating. In Sweden, the use of 2+1 roads (two lanes in one direction and one in the other) have led to a dramatic drop in fatalities by separating the lanes with cable guardrail.
There are different types of crash barriers. In general, a crash barrier is a piece of traffic safety equipment designed to keep cars on the road and in the appropriate lane of traffic. When a car collides with the crash barrier, the barrier is supposed to gently redirect the car back into the roadway, ensuring that it does not run off the road or into another lane of traffic.
When using a crash barrier of any type, it is important to address the ends or terminals of the barrier. Way too often we see the turn-down ends being installed. International Road Federation, as part of the Decade Of Action for road safety, has issued a policy statement ( http://www.irfnews.org ) in which they urge all road authorities around the globe to ban the turn-down and “fishtail” ends being used.
There are several full-scale crash tested terminals available.
These terminals meet the EN 1317 Standard and will bring an errant vehicle to a complete and controlled stop within the criteria of the Standard.
Interestingly enough, we have been taught that “speed kills”. I claim that it does not – it is the way we stop that kills. Actually, we see three impacts at a collision. 1. The vehicle impacting the obstacle. 2. The bodies of the occupants impacting the interior of the vehicle. 3. The organs inside the body impacting the inside of the chest.
The solutions I’m talking about address the first impact but will also have a crucial effect on the third impact. If we can absorb the kinetic energy and prolong the time it takes for a vehicle to come to a complete stop then we can also minimise the forces that go into the body.
At about 20G, internal bleeding starts to occur, so this is one of the criteria (to stay under 20G) that must be met in full-scale crash testing of these products.
Sometimes, I realise, there are good intentions behind unprotected obstacles at the roadside. It is good, for example, to put up signs because they give guidance to drivers and avoid last-minute decisions. But, in some cases, they create an obstacle that potentially cause a fatality.
I have seen several turn-down ends and fishtails on Malta’s roads. But I also noticed potential, such as with unseparated sections of road that, with a relatively small effort, could be turned into 2+1 roads as we have in Sweden.
Peter Bergendahl is a senior director at Trinity Highway Products International, Sweden.