Ealing found evidence to support its theory when the lights failed one day at a busy junction and traffic flowed better than before. Councillors have approved a report which recommended that they “experimentally remove signals since experience of signal failure showed that junction worked well.”
I observed a similar phenomenon sometime around March of 2009 at an intersection near where I work. For about a week, the intersection shown below, which is usually regulated by stoplights (including a left turn arrow), was regulated solely with stop signs as a 4-way stop. My personal observation was that traffic flowed no worse than usual, and if anything may have been better. Ultimately, I think the best solution for the intersection shown below is multi-lane roundabout.
View Intersection where stoplight was out of service in a larger map