A frozen fuel line can be the result of extremely low temperatures that cause the water vapor in the gas tanks to blend with whatever fuel is in the line at the time and freeze. While taking care of a frozen fuel line is rather inexpensive, it can be a source of frustration. It's best that motorists take steps to keep their fuel line from freezing.
The reason that a car doesn't start whenever the fuel line has frozen over is that fuel is unable to flow to the engine.
One of the things that motorists can do to prevent their fuel line from freezing is to keep their battery fully charged. One of the best ways to fully charge a battery is to drive it for an extended period of time. Short trips can deplete the battery's overall charge.
It's also recommended that drivers keep their automobile's fuel system in good condition. This can be done by adding fuel additives such as fuel line antifreeze to the fuel system. Keeping the fuel tank as full as possible is another good idea to keep the fuel line from freezing over. Doing so lowers the amount of moisture that is in the fuel system at any given time.