APM: 16 Location: SR 4 and Port Chicago Hwy, Concord Reassurance shield after the SR 242 interchange. APM: 17 Location: SR 4 and Willow Pass Rd, Concord Reassurance shield after Willow Pass Rd as we head out of Concord. APM: 17 Location: SR 4 and Willow Pass Rd, Pittsburg As we head out of Concord, we’ll enter Pittsburg. … Continue reading California State Route 4, SR 242 to SR 160