lower elevation connector 280 includes an upper portion 282 that attaches to the base at the higher elevation and a lower portion 284 that attaches to a base at a lower elevation connector 280 includes sides 286 and only two holes 228 for bollards fig1 depicts a connector 290 that also functions as a vehicle passage through an anti ram system connector 290 is interconnected to spaced bollard sections 300 which are only partially shown attached to opposite sides of connector 290 are 180 u00b0 connector parts 292 similar to 180 u00b0 connector 230 or connector 272 connector parts 292 each include a hole 228 for a bollard and are connected to bases as described above other suitable structure may be provided for interconnecting connector 290 with adjacent bases connector 290 comprises one or more retractable or removable bollards 296 which can be conventional in the depicted embodiment bollards 296 retract into channels referenced by 298 connector 290 also comprises entrance and exit ramps 300 301 which lead to an elevated central section 304 which is approximately the height of the adjacent bases but could be higher or lower the height of the central section in one embodiment is sufficient to accommodate channels 298 for the bollards in use the bollards are normally extended as shown in fig1 and retracted when.