SAN FRANCISCO (AP) — Shuttle drivers who ferry tech workers between Silicon Valley and San Francisco have voted for union representation.

The San Francisco Chronicle reports (http://tinyurl.com/nf3ltp2) that drivers working for Compass Transportation voted 104-38 in favor of joining the Teamsters union Friday. They voted at secret polling booths set up at several locations near driver rest areas in South San Francisco and San Jose.

The company drives workers to Apple, Yahoo, eBay, Zynga and Genentech. Drivers who serve Facebook voted earlier to unionize.

Union leaders said that tech shuttle drivers are underpaid, overworked and unfairly compensated for time spent on the job.