Officials at the Westfield Valley Fair mall are gearing up for the biggest shopping day of the year Friday with improved signal lights and added traffic control, after dozens of cars were gridlocked in the mall’s parking garages for up to three hours last week.

The region’s busiest mall worked with the city’s department of transportation to adjust the timing on signal lights at mall entrances in order to improve traffic flow. It has also hired personnel to manually direct traffic on site for the entire holiday season, according to Senior Marketing Director Caran Fisher.

City staff monitored traffic patterns at Valley Fair and sought feedback from mall staff following major congestion last week, according to Kenneth Jung, senior engineer with the city’s department of transportation. Crews have made signal timing adjustments at several intersections in the area to account for the anticipated traffic on Black Friday and beyond, including the intersections at Forest Avenue & Monroe Street, Monroe Street & Stevens Creek Boulevard and Interstate 880 & Stevens Creek Boulevard, according to Jung.

Several shoppers reported being trapped in a nightmarish traffic backup inside the mall’s parking structure last Saturday. Some reported waiting for more than three hours to exit the structure, while one family reported taking an Uber to leave the mall, opting to return for their car the next day.

Mall management said nearby signal lights — which only allowed four cars to move through at a time — were to blame.

Black Friday shopping is typically the busiest shopping day of the year at most malls throughout the country, and this year will likely be no exception.