Abstract: Improved devices for controlling vehicular traffic are disclosed. The present invention permits the installation of collapsible bollards or posts to create a barrier to vehicular traffic. The bollards disclosed use an internal latch bar and a hinged connection allowing them to be collapsed using an ordinary fire hydrant wrench, thereby permitting access by fire and emergency vehicles to the areas protected by the bollards. Moreover, in the preferred embodiment, a novel spring-loaded latch bar, entirely contained within the bollard and protected from the elements, permits the bollards of the present invention to be reset in a locked position without the use of a hydrant wrench or other tools. Other embodiments disclose how the bollard may be re-locked without the use of tools when the bollard is returned to an obstructing position.