Xavier Nailing, 44, a hospital custodian, said he routinely rides without paying a fare, and does not fear the consequence of detection.

“Nothing ever happens when someone writes me a ticket,” he said. “The last time someone wrote me a ticket I looked at the cop and said: ‘You know what, how long have you been on the force? You can write me that ticket but you’re going to stand there and watch me tear it up because I know it’s not going to be enforced.’ ”

This remains a work in progress. Some stations on the system have gates, some do not. Some of the gates are locked, some slip open with a simple push. The whole process has been ensnared in years of delay, reflecting the complex web of underground trains, light-rail trains and buses that form the public transit system here. Its opponents continue to question whether the supposed recovery of lost revenue would cover the $46 million installation cost, plus $103,000 a month in maintenance.

Still, a locked-entry subway finally appears at hand, with officials saying that 192 turnstiles at 42 stations will be locked and ready for business by the summer. It is the latest milestone in Los Angeles’s halting march toward imposing a mass transit system on a region that has traditionally been so loyal to the automobile.

“I think the honor system is great, but if people abuse it then this is what we end up with,” said Peter Eaton, a film director, as he entered a subway station. “I know it’s just the nature of the times we’re in. I would prefer the way L.A. has been doing it and not change it, but on the other hand I can see doing it the way other cities do it.”