The collision was reported at about 5:25 a.m. on the track near the intersection of Ninth and S. Railroad avenues, spokeswoman Christine Dunn said.
The northbound train No. 101 struck the truck at Ninth Avenue and dragged it all the way to Fifth Avenue before coming to a stop, according to Dunn. The driver of the pickup truck died at the scene, she said.
No passengers on the train were hurt, Dunn said.
By 8:45 a.m. Caltrain officials opened the southbound track for service at reduced speed. The northbound track remained closed at that time. By 9:15 a.m. officials had opened tracks in both directions.
Delays are expected to continue throughout the morning commute, Dunn said.