roads and highways
different countries in Europe, North America and Canada.
A gradual, but accelerating and seemingly inevitable change from petrol and diesel engines, to hybrid and electric vehicles (EV), means more than initially meets the eye. Service stations and both private and public car parks are certainly evolving, with EV charging points being installed to cater for rapid growth in vehicles needing to be plugged in mid-journey.
What many may not be aware of, is the inherent safety risks and necessary precautions associated with EVs and hybrid vehicles. For instance, electric vehicles have certain unique characteristics in the event of a fire. Storage of an EV after an accident, or after a fire has been extinguished, can be a very important consideration, due to the risk of the vehicle reigniting later on.
Meridiam project companies have been looking into these risks and exchanging knowledge gathered, while initiating some mitigating measures, such as developing training programmes with asset operating companies.
It is increasingly important for them to do so. EVs and hybrid power currently account for about 2% of all cars sold globally, but the proportion is growing and expected to increase exponentially. According to the EV sales database EV Volumes, 2.1 million ‘plug-in’ vehicles were sold in 2018, 64% higher than 2017.
Meridiam projects are responsible for operating over 2000km of roads and higways, across 12 different countries in Europe, North America and Canada.
Many of Meridiam’s highways projects contain at least one tunnel. Safety plans for responding to incidents, especially fires, are a vital part of operations for these projects, which are exchanging knowledge and best practice via the Meridiam Tunnel Club (see box 2).
The story of unique risks of EVS and hybrid vehicles starts in Europe, partly because several high-profile and well-documented fires have occurred in European tunnels. The Mont Blanc disaster of 1999 and the Gotthard road tunnel fire in 2001, tragically claimed 39 and 11 lives respectively.
Since then, the safety of the operation of road tunnels in general has improved a great deal through regulations introduced since 2001, with greater use of fire detection, ventilation, CCTV and communication technology, for example.
One major Meridiam highway project is the A5 Ostregion PPP north east of Vienna, covering 51km of A5 motorway, including four tunnels.
The Chief Technical Officer of the project concessionaire, Bonaventura Strassenerrichtungs, is Peter Pelz:
“Our tunnels are all twin-bore with single direction traffic, so avoiding contraflows and all four are relatively short and have safety passages and the latest fire safety technology. So, while safe operation of tunnels is paramount to us, consideration of risks with regard to EVs applies equally to the whole network, including vehicle storage areas,” Peter says.
Bonaventura and its operating contractor have experience of dealing with an EV fire incident, which occurred outside of the A5 tunnels and was dealt with safely. Subsequently, Bonaventura has undertaken studies of EV safety issues in partnership with the A5 project grantor, Austria’s national highway authority ASFiNAG.
The results reveal there is little evidence that EVs and hybrids are any more likely to catch fire than conventional cars, but battery powered vehicles display distinct characteristics in the event of a fire.
For instance, they can ignite explosively and burn at very high temperatures, giving off toxic smoke due to chemicals present in the batteries. Use of water is appropriate for fighting the flames, but about double the time and quantity of water is usually needed to fully extinguish the fire.
Special consideration then has to be given to cooling and monitoring the vehicle, due to the risk of reignition, which is why storage of damaged EVs – separately from other flammable materials – is critical.
“Here at the A5 project, we have produced a handbook for the motorway operating company and implemented training for staff and operatives on how to respond appropriately, including with suitable storage areas for recovered EVs and hybrid vehicles,” Peter says.
Bonaventura and its operating contractor have a limited role in recovery and safe keeping of fire damaged vehicles, which remain the responsibilities of local authorities. The operator is establishing concrete boxes for storing and shielding recovered EVs, however and Bonaventura has been liaising with local fire services.
“We have found firefighters are generally not very well prepared for the additional and unique treatment required when dealing with EVs and hybrid vehicles. Likewise, manufacturers’ recommendations do not say enough about storage and cooling requirements after fires,” says Peter.“ It is important for these things to be thought through and acted upon, at a national level and by operators of individual highway projects. The Austrian Ministry is aware of the issues and ASFiNAG is carrying out additional testing.”
Miami Access Tunnel (MAT), the concessionaire company responsible for the Port of Miami Tunnel (POMT) project in Florida, has also been investigating the particular characteristics of electric vehicles. As part of efforts to mitigate the risks, training on EVs and how to deal with incidents has been held for ‘first responders’, in partnership with POMT’s O&M contractor and the Miami Dade Fire Department, with sponsorship from the manufacturer Tesla.
“We had a team from Tesla come in and demonstrate to operatives and the Fire Department the ins and outs of Tesla vehicles, such as where the batteries are located and housed, where the cables run and how and where to cut them,” says MAT Chief Executive, Chris Hodgkins.
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