Most of Sacramento's light rail is quiet zones (bell-only for the train) or street operation (also bell-only), but they do blow the horn for a few crossings (such as Jackson Hwy aka SR 16) - standard long-long-short-long though often a bit condensed. Light rail doesn't have whistle posts at that crossing, though the freight line next to it does. If there are problems, as with the current signaling reconstruction east of Sunrise, quiet zone goes out the window and trains stop before each crossing then blow the horn with bell on through at restricted speed, even with the gates down (probably working on the backup track circuit).

BTW, the gates DO work on the track circuit. Old Siemens U2s and CAFs all shunt them just fine, even with service on only 1/2 hour headways (mostly 2-3 car trains) and nothing for almost 12 hours overnight. In the winter, with rain and tule fog. So one might wonder why certain other lines are having so much problem with that despite bigger, heavier equipment?