In California, if there is not a parallel alternative route for bicycles to take, they are allowed on the freeway. Many parts of the 101 freeway fit this exception.
State highway 130 (look it up on google maps) is a favorite of cyclists. It is a two lane state highway with a 40 MPH speed limit. for most of its length, there are no shoulders. In many places, the white line on the edge of the lane is also the edge of a vertical cliff. There are places where I have seen an SUV in front of me with one wheel on the white line, and the other on the double yellow line because the lane is so narrow. The road is so winding that there are very few places where you can even get to the speed limit, let alone exceed the speed limit.
But bicyclists love it because it was built to allow horse drawn wagons to haul heavy loads to the top of a 4000' peak, so it has a very gentle grade, and there are great views along its entire length.
In California, if there is not a parallel alternative route for bicycles to take, they are allowed on the freeway. Many parts of the 101 freeway fit this exception. State highway 130 (look it up on google maps) is a favorite of cyclists. It is a two lane state highway with a 40 MPH speed limit. for most of its length, there are no shoulders. In many places, the white line on the edge of the lane is also the edge of a vertical cliff. There are places where I have seen an SUV in front of me with one wheel on the white line, and the other on the double yellow line because the lane is so narrow. The road is so winding that there are very few places where you can even get to the speed limit, let alone exceed the speed limit. But bicyclists love it because it was built to allow horse drawn wagons to haul heavy loads to the top of a 4000' peak, so it has a very gentle grade, and there are great views along its entire length.