Creative Traffic Control
If you need to control or restrict vehicular traffic in an unobtrusive way, bollards do the job. Spacing can be done to permit small, special-purpose vehicles inside while keeping sedans and trucks out. Four feet is a good height for a bollard, but they can be lower if you only want to deflect tires. Remember, anything over seventeen inches can be in conflict with vehicle bumper overhang. Because bollards are relatively small, they can be made to be removable from ground sockets and relocated as needs change. They can also be retractable, something necessary to allow first-responder access in emergencies.
Even though bollards are relatively unobtrusive visually, they can be decorative. You can incorporate lighting. They can serve more than one purpose. The design can look like the original mooring bollards for ships. Boats are a design inspiration for many, but you can dream up lots of innovative and imaginative options.