A portable version of those airport body scanners that travelers loathe might soon be used to screen commuters at subway and bus stations across the country.

The Los Angeles County Metropolitan Transportation Authority announced in August it will become the first to deploy the technology this fall, adding an extra layer of security to the country’s third-largest transit system. Amtrak and New Jersey Transit are considering it, officials said. The system has been tested at Washington’s Union Station.

Los Angeles International Airport is exploring its use in pre-security checkpoints. And more major transportation agencies may incorporate similar technology as they harden their properties against threats, experts say.