News

September 24, 2002

Lanes along Delaware highways will be easier to follow at night if a little-noted DelDOT project continues to proceed the way it has been going. Both embedded reflectors and reflective striping tape are going to get a thorough look-see along the Smryna-Dover toll road.

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.

2002. All rights reserved.

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