When installing a Bollard, how close should the Bollards be spaced apart?
Depends on your application. If pedestrians need to ingress and egress through the bollards, no closer than 3′ apart. More standard would be 4′ apart. Do not space by more than 5′ if you need to stop automobiles.
If you are protecting a building and pedestrians arent expected to pass by the bollards, you may want to space them closer depending on the strength of the bollard.
There’s a good blog about bollard spacing here.
Bollards provide one of the simplest means of controlling access by vehicles. The distance between the bollards will determine the types of user that will be able to pass. The recommended minimum gap of 4 (four) feet will allow access by pedestrians, people with strollers, wheelchairs, bikes, and motorcycles – but should prevent passage by most vehicles. The preferred gap of 5 (five) feet provides a little more space for people to pass and is still inaccessible to most vehicles.