In this episode, we commence a 3-part exploration of Route 4. This episode starts with all things Route 4: The 4th state route, DOH and Legislative Route 4, and pre-1964 Route 4, finally setting on today’s Route 4. We talk about the LRNs that make up today’s Route 4: LRN 106, LRN 75, and LRN 24. We focus on the first segment of the route, from I-80 in Hercules to I-5 in Stockton. We talk about Route 4 in cities such as Hercules, Martinez, Concord, Antioch, Brentwood, the wetlands, and the Port of Stockton. We also talk about freeway segments, projects, and names along the route. The subsequent two episodes continue Route 4, with 3.03 focusing on the Stockton Crosstown Freeway. For more information and additional links, see this episode's page on our forever home at caroutebyroute.org.