IT was a Thursday morning, and Robert Treat, the chief technology officer for an Internet company, was looking forward to some uninterrupted time to get work done on the train from Baltimore to New York. Leaning back, hot cocoa at the ready, he logged on, scrolled through a few e-mails and then ... no more Internet. He logged on again, managed to connect for a few minutes, and soon enough: nothing.

Was it just him? He glanced up to see the woman across from him looking around too, with a similar expression of annoyed concern. “Death by a thousand cuts,” he said resignedly. Another commute. Another agonizing attempt to use the Internet on Amtrak.

For rail travelers of the Northeast Corridor, the promise of Wi-Fi has become an infuriating tease.

First introduced on the Acela amid a heavily promoted marketing campaign two years ago, its press release promising “fast, reliable and consistent connectivity,” Amtrak’s wireless service has instead turned into a source of mockery on blogs and a daily source of angry messages on Twitter and other social media.

“Couldn’t get enough signal on my laptop to complain how bad the Wi-Fi is on my train,” wrote MattSullivan101 on Twitter last month. “Well played, #amtrak,” he continued, “but you missed my phone.”