After a comprehensive review of the history of
the IFC’s current impact protection requirements,
the NPGA study concluded that the provisions were
likely intended to provide protection against low-speed automobile collisions. Interestingly, however,
the review found no indication that the performance
capabilities of IFC-compliant impact protection have
ever been tested.
In other words, the IFC provisions appear to have been
based on a very general goal, without a tangible standard by
which to evaluate the success of a given barrier in meeting
Phase 2: Collision Testing
To gain a better understanding of the benefits and
limitations of bollards and propane cabinets, the study next
undertook full-scale collision testing. The goals of this phase
were as follows:
1. Evaluate the performance of vehicle impact protection
bollards complying with the IFC; and
2. Compare the level of protection provided by bollards with
that of cabinets used to secure and protect propane cylinders.
To accomplish the first objective, the study evaluated the
relative performance of code-compliant bollards under various
combinations of soil and pavement conditions, vehicle weights,
impact speeds and impact heights.
For example, several tests were conducted with the
“restrained” bollard illustrated in Figures 1 and 2, a very robust
performance level for a code-compliant installation.
Other tests used the “unrestrained” bollard illustrated in
Figure 3, a less robust performance level.
Similarly, propane cylinders placed in industry-standard
cabinets were tested to evaluate key variables, including cabinet
material (steel vs. aluminum); anchored versus unanchored; and
with or without concrete backstops (to simulate the presence or
lack of a rigid exterior building wall behind the cabinet). Again,
collision testing of the cabinets involved various vehicle weights,
vehicle speeds and impact heights.
Cabinets & Vehicle Impact