How do they do that? is a series for The Source that explores the technology that helps keep Metro running and passengers and other commuters moving. Some of it applies directly to the trains, buses and freeways and some of it runs in the background — invisible to nearly everyone but essential to mobility in our region.

Hands-free intercom for wheelchair patrons.

The subway gates are being latched one station at a time and given that we are an advanced civilization, Los Angeles seems to have survived. (The Red and Purple lines are on schedule for latching completion Aug. 5.) For most of us the gate latching has turned out to be no big deal. We pull out our TAP cards — either plastic TAP or TAP-enabled paper tickets — and we march on through.

But what if we were commuting in a wheelchair?

A new hands-free intercom system developed by Metro for ADA patrons opens the gates automatically upon verbal request by a wheelchair patron or silently, if the patron cannot speak.

How do the subway gates unlatch for customers in wheelchairs?

Attendants on duty 24/7 monitor the wheelchair-accessible gates on closed circuit TV. As passengers in wheelchairs approach the special hands-free intercom (a silver box with a blue wheelchair sign next to it) a round camera above the hands-free intercom transmits the image to attendants standing by to help. Or, if they are able, patrons can press a red button to call for help with the gate. The attendants also are alerted to the presence of a wheelchair by a small sensor posted below on the same column.

The attendant verbally greets the wheelchair patron and, if possible, the patron confirms verbally that assistance is required. If the patron cannot speak, the attendant can see that and respond by triggering the ADA gate to unlatch. When it does, the patron can proceed through the opened gate.

The technology required for this innovation is not unusual or particularly high tech — camera, telephone, speaker, lights and an electrical connection to the gate that facilitates the opening of it remotely. Yet used in partnership in this particular combination, it is a simple but innovative way to make travel a little easier for patrons in wheelchairs.