Reports suggest that up to 1 in 7 vehicles (14%) on US roads may be uninsured. Based on vehicle population figures this indicates that over 37 million vehicles are being used illegally. Although insurance is compulsory in 49 states and most states suspend vehicle registration when a policy lapses, there are loopholes in the system and current enforcement is not 100% effective. The safety risk of accidents posed by uninsured drivers is high, with additional legal complications for any innocent parties involved. Meanwhile there are also issues of congestion caused by illegal use of vehicles that need to be addressed.