The cross-town drive to work this morning was the clearest of traffic I've ever known it. And apart from the first and last hundred yards and a small patch on the Madingley Road/Queen's Road/Northampton Street roundabout the roads were fine. The weather and road conditions weren't bad yesterday either -- I've got to think it's just that Cambridge traffic is so on the edge of what it can bear that the slightest incident somewhere in the environs can gridlock the entire city.