because of construction or an obstruction in the road, and then the person in the lane they need to enter just rides the tail the car in front of them, preventing the merge?
Can't remember the name of the technique.. I want to say it sounded like "toosh lag lasso driver" but I know that's not it. I can't remember for the life of me what it's called. Been a long time since I was in drivers ed. Anyway, I see it all the time here in Utah though. Usually when everybody is going 15-20mph on the I-15.