It would be great to have the option of selecting a concrete barrier as a buffer option (vs bollards). They can be used to separate traffic directions on heavy arterials,and I’ve seen them used to separate a cycle track from car lanes.
This link provides a diagram: http://www.bushconcreteproducts.com/wp-content/uploads/FHWA_BARRIER_SHOP_PRINT.pdf
And more information is available here:
This website provides diagrams with dimensions for 3 variations, a F Shape barrier, a Jersey barrier, and a constant slope barrier.
Perhaps a separate object type to buffers could be added, a barrier section, and you could choose from the 3 types?