drop use of customary units and only use International System of Units (metric system) for all federal highway signage.

The United States is one of only three countries still using the standard system of units and measures in people's daily lives. Except for the United States, Liberia and Myanmar, the rest of the world converted entirely to the International System of Units (SI or Metric System) decades ago. It cost money and confusion to have two types of measuring systems in use in the United States. The time is well past due to finally drop the customary system of units in daily use. The most visible way to effect this conversion is with federal highway road signage by replacing speed and distance markings for motorists. This will help convert general use of SI in other parts of people's daily lives and retire the customary system for good. Government, business, medicine, science already use SI.