How Dangerous Is A Hybrid Vehicle?

While most legislators are looking to hybrid vehicles as a savior for the domestic auto industry that will also reduce greenhouse gas emissions and our dependence on foreign oil at the same time, hybrid vehicles do pose a real danger during both normal maintenance operations and in emergency situations.

Emergency responders are being taught to deal with hybrid electric and electric vehicles to minimize the danger of electric shock after a crash, or during an extraction. Currently, hybrid batteries carry as much as a 500V charge, depending upon the make and model. When the Chevy Volt and other plug-in electric vehicles hit the market, that figure will double to 1,000V. In addition, mechanics face a risk while performing normal maintenance on a hybrid electric or electric vehicle.

Emergency responders have been taught to deal with the dangers of gasoline in crash situations, and a top priority is to get the vehicle turned off. While gasoline leaks can still pose a danger to the rescue crew and passengers who may be trapped in the car, a vehicle that is turned off is less of a hazard to everyone involved.

Hybrid electric vehicles have various shut-off and safety mechanisms to help protect workers and passengers in a damaged vehicle. For example, the current generation Toyota Prius automatically disconnects its high-voltage battery when the vehicle's airbags deploy. Earlier models have a manual disconnect. The Honda Civic also has a manual disconnect switch, which is located in the rear of the passenger compartment, behind a service plate. The Ford Escape has a lift-out switch that isolates the electrical system from the rest of the vehicle.

In most cases, the isolation procedures for hybrid vehicle electrical systems were designed with maintenance - not emergency response - in mind. Manufacturers recommend waiting an additional 5 to 15 minutes for a vehicle's high voltage capacitors to fully discharge, further reducing the shock hazard. In an emergency situation this may not be possible.

Legislators and disability advocates have already noted that hybrid electric vehicles operate in electric mode at slow speeds and may not make adequate noise to warn pedestrians of their approach. Equally dangerous is the fact that many hybrid models look identical to their gasoline counterparts, and emergency and maintenance personnel may not be able to identify the additional hazards the vehicles can pose.

As more hybrid and alternative fuel vehicles are released into production, expect legislation to regulate and standardize hybrid identification, minimum noise levels and emergency disconnection requirements. In all likelihood, these regulations will raise the hybrid premium even higher. At the same time, these concerns demonstrate why hybrid vehicle design and production should include some healthy deliberation.

Photo Credit: Jon, via Flickr