If you ride BART, you've noticed the crowds, right?

With trains at capacity during every rush hour -- who knew so many people could become such close friends? -- BART is testing a new seating layout that will allow more passengers to board each car.

"New seating layout" is a little bit of a euphemism, actually. What BART is doing is replacing seven double seats with seven single seats on a group of test cars. In other words, each of those cars will have seven fewer seats, but more room for passengers to stand.

BART spokeswoman Alicia Trost said via email that a total of 20 of the system's 669 cars will be retrofitted with the test layout, and seven are already in service. She adds that it's not clear yet how many extra passengers might fit aboard BART's aging cars with the new configuration -- that's one of the points of the test.

The agency is looking for passenger feedback on the new configuration -- go to www.bart.gov/testcar.

While formal study results still haven't come in, Trost says she conducted her own informal survey when she got on one of the retrofitted cars last week, on the Pittsburg-Bay Point line.