The Vancouver Sun has another interesting article (subscription required)
on traffic today. The gist: traffic congestion is terribly unpredictable.
Buried in the analysis is, I think, a larger point.
Studies by the Greater Vancouver Regional District suggest one reason the daily commute is getting snarlier is that too many jobs are being located in new suburban office parks that are difficult to serve by road and almost impossible by transit.
The office parks tend to locate where land is cheap. The people who work in them have no choice but to drive along roads that were not planned to serve such developments.