Multiple factors
I believe the biggest one is probably not ebough long haul truckers
Companies that need their peouct delivered are sniping off truckers from other jobs they already had on the books by paying them more to go and deliver their goods instead
I hear it from every business I regularly buy from, I know the store owners and talk with them about what they are experiencing, because its affecting their inventories
Rather than otr drivers, they’re going to regional. New Hook and Drop loads are better for truckers because they don’t have to wait to load and unload at the docks.
Also consider the HOS (hours of service) mandates by the DOT.
Per this trucker, they were sending truckers away.
And the port isn't running 24/7. It's closed for parts of Friday and Saturday, and all of Sunday.