A large-capacity automated scale capable of weighing trucks while they are moving is being developed for the military at the Oak Ridge National Laboratory in Tennessee by scale-maker Intercomp based in Minneapolis.

The first commercial prototype could be ready in six months and deployed to army units worldwide. Its main purpose is to quickly and accurately weigh cargo planes to make sure they are not over their carrying limits.

The scale looks like a speed bump over which vehicles are driven at speeds less than 5 miles an hour. Data on the vehicle tire hits are fed to a computer which determines the total weight. The entire scale can fit into a 4-by-4 foot crate and takes 15 minutes to set up, army officials said.

Army officials added that with further refinements it could be used to weigh trucks traveling faster than 5 miles an hour with comparable accuracy. If so, this could mean shorter lines at commercial truck scales.