|
Larry
Prince, supervisor of pavement marking, told Delaforum that two-
and three-year tests of embedded highway reflectors, begun
during the administration of Secretary of Transportation Anne
Canby and now being wrapped up, showed that some manufacturers
apparently have overcome what has long been cited by Delaware
Department of Transportation as the principal reason the devices
have not been used in Delaware: their tendency to shatter when
the roads are cleared of snow.
Only nine of 500 Stimsonite
reflectors and none of the 60 Ray-O-Lite ones were lost, he
said. The
|
test installations were in
southern New Castle County. A third brand did not fare so well
and has been dropped from the project.
In previous trials over the years,
he said, the casualty rate reached or was close to 100%.
The better-performing varieties will
be installed for a further, more extensive test in spring, 2003,
along the section of Delaware Route 1 now being built between
Smyrna and Odessa.
Later installations along main roads
will depend upon what is learned about their effectiveness as
safety devices and maintenance experience, according to DelDOT
spokesman Michael Williams. "Being very expensive to install, we
expect that they may be funded only on limited projects," he
said.
|
|
|
DelDOT photo
You have to draw the
line somewhere -- DelDOT follows a rotating schedule to do
it annually on Delaware roads. |
Meanwhile, Prince said, the agency
also is about to use Route 1 near Dover to test a considerably
more economical product, Epoplex, an epoxy tape made by 3-M
Corp. which contains reflective beads of various sizes. Unlike
other tape on the market, it actually is better at throwing back
light when it gets wet.
He said
that DelDOT has been using tape to mark lanes for several years.
While the variety used temporarily, mostly in construction
areas, tends to unravel, there are more durable products on the
market. In one instance, tape put down in 1993 lasted nine years
before it had to be replaced this year, he said.
Tape
eventually will replace paint, which has to be renewed annually,
as the product of choice. "It definitely is going to be the
lane-marker of the future," he said.
Williams
explained why the experience with embedded reflectors here
seemed to run counter to what happens in many other places
around the country where using reflectors as part of highway
markings has been going on for years. Statewide in Delaware, the
snow-plowing standard is a form of zero tolerance. The blades
literally meet the pavement.
"Because
we have relatively mild winters, we have a bare-pavement policy.
Residents and citizens have come to expect this condition of
their roads," he said. In other jurisdictions, he said, it is
customary to leave about an inch or so of residue to to the
mercy of traffic.
In order
to catch the beams of oncoming headlamps and be good at what
they do, highway reflectors have to protrude slightly above the
surface of the road. They are plugged into shallow holes, about
an inch deep.
Prince
said he does not know if Delaware is the last state to use
highway reflectors, but said it is certainly among the last. He
agreed that they are generally recognized as effective safety
devices. They significantly increase drivers' visibility at
night and especially in inclement weather.
He said
the difference between the past and now is that the
manufacturers of two of the varieties tested set the plastic
reflective lens set in a metal casing. The 'old fashioned' ones
were all plastic.
The other
drawback to widespread use, he said, is cost. Each of the
varieties tested sell for between $28 and $35 apiece. The
national highway standard is to set them every 80 feet, or 66
per mile.
As a
result, Williams said, most jurisdictions which use them do so
on heavily traveled arterial roads. The reason that travelers
regard them as extremely common elsewhere is probably because
those are the roads which they mostly use.
Prince
said DelDOT estimated several years ago that installation of the
reflectors along Interstate and major arterial highways in
Delaware would run between $2.4 million and $5.9 million.
|
