Anyone who has owned a vehicle that had a 6 volts electrical system will know why the higher voltage of 12 volts is better in overcoming cable and contact losses. Modern cars have had to adopt higher voltages still to cope with the mild hybrid technologies of combined starter/generators.
110 volts is used on construction sites because the shock current that would flow is much higher when you are in a wet environment. The 110v transformers are centre tapped to earth to reduce to 55 volts the voltage you would experience between one live conductor and earth.
There are also precautions In your house where water is likely to be an issue. If you have a shaver socket in the bathroom then it's fed via an isolating transformer such that there is no voltage between the live conductor and earth. You would have to touch both conductors to receive a shock.
110 volts is used on construction sites because the shock current that would flow is much higher when you are in a wet environment. The 110v transformers are centre tapped to earth to reduce to 55 volts the voltage you would experience between one live conductor and earth.
There are also precautions In your house where water is likely to be an issue. If you have a shaver socket in the bathroom then it's fed via an isolating transformer such that there is no voltage between the live conductor and earth. You would have to touch both conductors to receive a shock.