Here is a highly detailed 1/10th scale model of a 42-inch tall jersey barrier. This has also been printed at 1/14th scale (71.4% scale of supplied 1/10th scale model) with success to fit with Tamiya semi trucks and other RC construction vehicles.
The barrier consists of one main body with two press-fit plugs for the fill and drain ports. You may need to perform slight scaling of the plugs to ensure they fit into the barrier properly with a slight press fit.
2 Walls and 8% Gyroid Infill
Manual Tree Supports were only used in the four corners and one other section highlighted below:
The rest of the overhangs were able to be printed without supports using bridging.
The two plugs have a small contact patch with the build plate, so a brim for those parts is recommended.
The included .3mf file is for Bambu Lab printers and includes prints for both 1/10th and 1/14 scale barriers.
Inspired from: https://www.remcon.com/products/barriers/guardsafe/