UPDATE 1:50 p.m.: LAPD has arrested about a dozen protesters who refused to move from the intersection of Century and Sepulveda boulevards near LAX.
The arrests came after LAPD officers called it an "unlawful assembly."
Protesters near the intersection could be heard chanting "Shame on you!" as the officers cleared the road.
While the protest has led to detours on the main route into and out of the airport, it is not disrupting operations inside the terminals.
UPDATE 1:22 p.m.: Hundreds of union members have begun a permitted march near the entrance to LAX, where travelers have been warned to arrive early in case of traffic snarls, the Associated Press reports.
Members of the Service Employees International Union began marching at midday Wednesday, with a large police presence standing by. The union is in a dispute with an airport services company that no longer has SEIU contracts.
The march began several hours after the end of the airport's peak travel period in the morning. The LAPD planned a series of moving road closures to divert traffic around the march.
UPDATE 8:45 a.m.: It’s pretty quiet at LAX Wednesday morning. The labor action has been rescheduled to between noon and 2 p.m. along Century Boulevard near the airport.
Officials are advising passengers to avoid the intersection of Century and Airport boulevards during that time.
This is not a strike because no one is walking off the job.
The march is being lead by SEIU, which says Aviation Safeguards walked away from its contract with employees, leaving about 400 people unrepresented and without health insurance.
SEIU represents non-flying workers, including security guards, skycaps, and janitors.
Aviation Safeguards says that its employees voluntary walked away from the union and are earning more now than they did under SEIU's representation.
PREVIOUSLY: Protesters are beginning to gather for a labor march set for Wednesday that could delay Thanksgiving eve travelers at LAX on one of the busiest travel days of the year.
Members of the Service Employees International Union are expected to march between 11 a.m. and 4 p.m. Wednesday outside the Century Boulevard entrance to the airport.
The union is in a dispute with an airport services company that terminated SEIU contracts last year.
Airport officials say travelers should add 90 minutes to their planned airport arrival time on top of the usual two hours before a domestic flight and three hours before an international flight.
All airport entrances will remain open. Officials report that traffic in and around the airport has been flowing normally during the day's peak travel period, which began at 6 a.m. and ends at 9 a.m.