| BOLLARD TESTING
Annual Showcase 2020 | Intertraffic World 169
Above: Pexco’s
latest City Posts
have been
implemented in
Florida, following
stringent impact
testing (right)
conducted in warm summer
temperatures, and a further five
were conducted in cold winter
conditions. The upright condition
of the posts and the retention of
reflective sheeting were evaluated
after all ten impacts were concluded.
A report was then published and
available to both member state
agencies and the manufacturer.
It is important to note that this
standard test procedure conducted
by an independent state agency
was the first of its kind nationally
to produce results that allowed for
direct comparison of one brand
and model with another.
While not a side-by-side test,
this uniformity demonstrated how
various products performed relative
to one another when subjected to
the same test regime.
In the mid-2000s, it became clear
that a more severe test was needed
to measure the improved durability
of recently developed posts for use
on high-volume, high-speed express
lanes. For four years, the NTPEP
worked to establish a new protocol,
with the goal of developing a
50-impact standard. These efforts
were ultimately unsuccessful, in
part because of limited manpower
and available funding. The effort
was abandoned in late 2010.
In 2012, the Texas DOT contracted
with the Texas A&M University
Transportation Institute (TTI)
to develop a new test method for
evaluating the impact performance
of delineators for express lane
applications. The results of this study
were published in February 2015. As
stated in the study, “Currently, the
Texas Department of Transportation
selects products based primarily
on cost and only requires that
delineators survive up to 10
impacts regardless of application.
“This testing requirement is
effective in preventing some failures;
however, it does not adequately
evaluate the resilience of delineators
used in high-durability impact
applications, low speed angled
impacts, or heavy vehicle impacts.”
NTPEP contracts
The work of NTPEP and TTI
intersected in 2018 when the
Tennessee test deck for flexible
delineators was superseded by use
of TTI’s proving ground in Bryan,
Texas. The test vehicle required
was updated to reflect Manual for
Assessing Safety Hardware (MASH)
standards, and two different test
procedures were adopted. The first,
for metropolitan applications, tested
at a speed of 55mph to either 200
impacts or failure, whichever comes
first; and second, for high-speed
applications, tested at 70mph to
either 200 impacts or failure.
Sampling is the same as before, as
is the array of posts. The weathering
testing conducted under earlier
protocols was modified to produce a
chemical fingerprint of the polymer
used to manufacture a product via
ash testing.
This new test protocol represents
the state of the art in evaluation of
posts in the USA. The first agency
to implement an approval based
upon the new testing was the Florida
DOT, which used data generated
by TTI to pre-qualify posts against
the requirements of its new Express
Lane Marker (ELM). All three
models of Pexco’s City Posts meet
this specification and are approved
for use on high-speed managed
express lanes in Florida. It is safe
to say many more states will follow
Florida in utilizing this protocol. n