Warnings

• Because hybrid vehicles run on a combination of an internal combustion engine and an electric motor, they run quieter, and could post a threat to pedestrians. In a University of California test in 2008, blindfolded subjects could hear a Honda Accord--with an internal combustion engine--36 feet away, but could not hear the Prius hybrid, running on the electric motor, until it was 11 feet away.
  
  

Considerations

• A Western Michigan University study in 2008 found that a hybrid vehicle and conventional vehicle are equally safe traveling at 20 mph. Researchers said this was because the noise generated from wind and tires gives pedestrians enough warning.
  
  

Potential

• Hybrid vehicles pose a potential threat of electrocution to emergency responders who perform rescue operations at the scene of an accident. Ford's 2010 Fusion Hybrid and Milan Hybrid come with an emergency response guide, informing responders of the precautions to take with the vehicles, which have a 275-volt battery in behind the rear seat.