"The trick here is the sameish budget. So changing the material for the Bollard to something very strong and more flexible would be too expensive. I think the arms should be changed to simple, large heavy duty springs/coils and heavy duty spring loaded hinges for the bottom of each Bollard. This would make them much more impact resistant without any significant cost increase. If you wanted to get fancy, a simple pressure switch on one of the coil arms of each Bollard connected to a single LOUD alarm to alert drivers ASAP to stop. (Also to be put in the building maintenance budget, paint the bollards once a year 😁)."