A Weakened Link

End of freeway sign on US 101 northbound in Marin County, California

In most of Marin and Sonoma counties, US 101 is a freeway. But between Novato, in Marin County, and Petaluma, in Sonoma County, US 101 instead becomes a limited-access highway with cross traffic. While the highway remains divided, this section is a notorious bottleneck hampering traffic between Sonoma and Marin counties. This sign is on northbound 101 north of Novato.