What's the story behind airport chapels?

Over the years, I've peeked into airport chapels and never seen a single person inside. Yet 16 of the country's 20 biggest airports have them. Above is the first example of such a space in the US, Our Lady of the Airways Chapel in Boston's Logan Airport, built in 1951 for airport employees. Wendy Cadge, a sociologist of religion at Brandeis University, has studied these sacred spaces. "Often, it is local, historical and demographic factors, including the religious composition of the region, that influence decisions" about why they're created and how they're used, she writes. From Smithsonian:

By the 1990s and 2000s, single faith chapels had become a dying breed. Most started to welcome people from all religions. And many were transformed into spaces for reflection, or meditation for weary travelers.

The chapel at San Francisco International Airport, for example, known as the Berman Reflection Room for Jewish philanthropist Henry Berman who was a former president of the San Francisco Airport Commission, looks like a quiet waiting room filled with plants and lines of connected chairs. A small enclosed space without any religious symbols or obvious connections to things religious or spiritual is available for services...

Certain airports such as Chicagos OHare have strict rules regarding impromptu religious gatherings whether inside the chapel or out. Some use their public address systems to announce religious services. Others prohibit such announcements and do not even allow airport chaplains to put out any signs that could indicate a religious space.

"A Brief History of Airport Chapels" (Smithsonian)

(image: Randall Armor, CC BY-NC-ND)