I'd argue there is, you just need good locations to board.
One problem that faces my city, as an example, is that we have a community that is being built out in a mountain area. There is a 2 lane highway going up there and, as you can imagine, it gets absolutely jam packed. On a clear day you can do the trip in 10 minutes, during rush-hour it can take over and hour.
This is the perfect place for something like a toll and a park and ride location within the community.
But instead we are maybe going to spend 10s (or maybe hundreds) of millions of dollars expanding the road.
This concept works great for airport's economy lots. It's a bit crazy that it doesn't seem to work for anywhere but the top 6 largest cities in the US.