 It serves as a more urban alternative to the rural I-280, as US 101 runs through Peninsula cities closer to the Bay, while I-280 runs closer to the Santa Cruz Mountains and Skyline Boulevard.Through northern San Francisco, US 101 remains routed on congested city streets due to freeway revolts, leaving the city on the iconic Golden Gate Bridge.It then departs the immediate coast and continues through wine country and Redwood forests until it re-emerges coast-side at Eureka.