Reason is a regulation that went into effect October 16, 2020. "EPA reached a settlement agreement [DATA HERE] with California Air Resource Board (CARB) to shut down semi tractor rigs that were non-compliant with new California emission standards"
"The trucking issue with California LA ports, ie the Port of Los Angeles (POLA) and the Port of Long Beach (POLB), is that all semi tractors have to be current with new California emissions standards. As a consequence, that mean trucks cannot be older than 3 years if they are to pick up or deliver containers at those ports. This issue wipes out approximately half of the fleet trucks used to move containers in/out of the port. Operating the port 24/7 will not cure the issue, because all it does is pile up more containers that sit idle as they await a limited number of trucks to pick them up. THIS is the central issue."
This has nothing to do with Covid or not enough people to unload the ships. This is a self inflected economic disaster.