The big rig was traveling westbound on the 210 Freeway at about 3 a.m. when it crashed into the center divider near San Gabriel Boulevard, according to the Pasadena Fire Department.
The truck then burst into flames, but the driver was able to escape with minor injuries.
Arcadia police said after an inspection, it was found that the heat from the truck fire stretched the overhead wires that provide electricity to the trains. This required the splicing of new wire and other repairs.
Metro crews were working to complete all repairs by Sunday night, but Metro officials confirmed bus shuttles will be required Monday morning.
Meanwhile, Gold Line trains were running on their Sunday schedule between Union Station and Allen Station in Pasadena. Bus shuttles were running between Allen, Sierra Madre Villa and Arcadia stations. Trains are also running between Arcadia and APU/Citrus College Station in Azusa, according to Arcadia police.
Lanes near the crash site were blocked throughout the morning but were cleared by 3:20 p.m., the California Highway Patrol said.
The cause of the crash was not made clear.