 Instead, the California Department of Transportation (Caltrans) observes the overall direction of the highway and marks these portions as north and south.Local references to this portion of the freeway, including traffic reports, usually refer to the directions on this section as east for southbound lanes and west for northbound lanes.In the late 1990s, Caltrans began placing guide signs on local streets in the San Fernando Valley adjacent to US 101 which identified eastbound and westbound entrances to the freeway.