Forget high priced consultants and studies, just keep an eye on Twitter!
"The most interesting thing we found is that transit riders do not give
any positive sentiment at a particular time. They only give negative
sentiment," he said. Now, this may seem depressing if you work for one
of these agencies. "But that’s not very disappointing," Hasan said,
"because we found that the lack of negative sentiment is basically what
transit authorities should look for. If there’s no negative sentiment at
any given time, that means that things are running smoothly."
Science Confirms What We Know About the CTA and Twitter - The 312 - January 2012 - Chicago