The objective of the research was to evaluate the alternative methods which could potentially provide effective and durable delineation of roadways during wet-nighttime conditions. Following is a summary of conclusions for future procedures and materials which should be considered as a method to provide effective lane delineation during wet-nighttime conditions.

  • Snowplowable raised pavement markers should continue to be used on interstates and parkways. The installation process must ensure the markers are not placed on or adjacent to the pavement joint.
  • Lenses in the steel casting raised pavement markers should be replaced on a three-year cycle. The condition of the castings should be inspected as part of this process.
  • The pavement condition adjacent to the raised pavement marker castings should be monitored to ensure there is no failure adjacent to the casting.
  • Evaluation of the use of a recessed pavement marker should continue.
  • Rumble stripes (painting edge line and centerline markings across a milled rumble strip) should be routinely used on resurfacing projects on rural, two-lane roads. Guidelines have been developed for the use of an edge line and/or centerline rumble stripe related to the pavement width.
  • Evaluation of the grooved and inlay installations of the wet-reflective paint, tape and thermoplastic material should continue.
  • Current research for an alternative to the current “bare pavement” policy (which involves use of steel snowplow blades with full weight) should be continued. Alternatives to the current policy include use of an alternative snowplow blade or a method of reducing the weight of the plow blade applied to the pavement.

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