Did you ever notice when you're riding during a heavy traffic time and ahead of you is a clear bike lane that can be blocks long and to your left is bumper to bumper traffic and then just one car decides they want to use the bike lane and suddenly it turns into 7 or eight cars right away? I see this happen on Clyborn just before North Ave in the mornings sometimes.
I haven't seen that specific issue much, but it drives me batty when I see a car double-parked or idling in the bike lane and there's plenty of space about 100 feet in front of them that they could slip into.
It takes common sense and drivers can lack that attribute. Today I was in one of those motorized things on Damen which is one of my favorite streets to cycle. At the entrance to the Kennedy the cars were lined up to make a left onto the expressway. I looked in my right mirror and saw none of the bikes I had passed a minute or so beforehand. I signaled and went around the sitting cars briefly entering the bike lane and returning to the main driving lane which was then pretty clear. This differs significantly from the OP where the cars simply decided to use the bike lane as a second driving lane rather than a relief valve lane for only brief usage.
Yes, On the Harrison street bike lane crossing the river into the south loop. One does it, like a UPS truck, and then the rest follow behind.
Morning commute observations.
CLP has a point about the congestion, and when people don't do what David described to keep the flow moving, then the congestion increases all the more, motivating people to fast-run yellows, etc. because they still have to get to/from work, take a kid to a piano lesson, run mom to the doctor on the way to work, drop off the dog at the vet, and so forth. Elston was another very effective 1 1/2 lane of 2 lane each when when the drivers were making it work at rush hour. Since the bike lanes impeded this, drivers now use Waze to find other routes, including residential streets instead. A stop sign every block is still faster than a traffic lane that isn't moving. So back to what we see on Clyborn, when someone sees the cars can get through, they'll follow.