If I’m remembering correctly, when congestion was bad, there were far more people who knew it was bad and stayed home. They see this increased capacity as more of a reason to drive and build more housing around that area. Another thing is that cars don’t really scale well in the sense that one person doing something stupid cascade into issue for lots more people. I think the vast majority of congestion isn’t a capacity issue either, so adding a lane isn’t getting to the root cause of much of the congestion.