Aware of? More like "And on that day, OC railfans received a grim reminder..."
These are on the SCAX Orange County Subdivison south of Santa Ana and north of Oceanside. Most of north Orange County's ex-ATSF track is comprised of Quiet Zone crossings, so there are thusly much, much too many to list.
TUSTIN:
Red Hill Avenue (MP 177.9)
IRVINE:
Harvard Avenue, Irvine (MP 179.9)
SAN JUAN CAPISTRANO:
Oso Road (MP 196.2)
La Zanja Street (MP 196.8)
Verdugo Street (MP 197.3)
Del Obispo Street (MP 197.4)
Avenida Aeropuerto (MP 198.8)
DANA POINT:
Beach Road (MP 201.0)
SAN CLEMENTE:
Senda De La Playa (MP 203.6)
North Beach Pedestrian Crossing (MP 203.75)
Exact milepost numbers credits to
http://mikeamick.com/. Note that a fair number of crossings were upgraded with Safetran quad / ped gates during 2011, with the two major cut-ins (San Clemente and San Juan) occurring in 2012 and 2013, respectively. Of them Verdugo Street has been altered the least.
As for my two cents on QZ usage--it mostly addresses a noise issue. I have yet to see a Quiet Zone solve a major roadway's traffic problems, and in the cases of Red Hill and Del Obispo quiet-zoning actually made things worse. I do recall 1-mile backups at both crossings, due to rush-hour train and road traffic meshing in the most unpleasantly-synchronized mess I've seen out there. Of them, Del Obispo takes the cake for being "the worst" as it has been traditionally-congested, and is tightly sandwiched between two major intersections. For all three lights to be green and for the crossing to be open to road traffic is next-to-impossible, and during rush hour the queue of cars can stretch much, much further back.
But as a railfanning thing, Quiet Zones have been "a thing" for several years now. Like it or not, they're going to either stay, evolve into grade-separations as roads clog further, or--in the case of BNSF's lawsuit against the CPUC regarding the remainder of the San Clemente crossings--be fought off or mired in construction due to legal issues.