Roadside delineators are widely used to supplant pavement markings. They are a form of "traffic control device" as defined by the
MUTCD. Typically, roadside delineators are used on curvilinear sections of roadway, thereby enhancing the horizontal geometry so motorized vehicles may negotiate the curve. They are especially important roadway safety features during nighttime, or adverse weather, driving.
Roadside delineators may be flexible (plastics) or rigid (steel or aluminum). AASHTO/NTPEP only tests flexible roadside delineators. These may be either surface-mount or ground-mount style delineators. AASHTO/NTPEP conducts field performance testing, where a standard sedan impacts a test deck of delineators during summer and winter climate; the half year test constitutes a "test cycle." Also, laboratory testing is conducted on the sampled delineator specimens.
The national testing facility under AASHTO/NTPEP auspices is operated by Tennessee DOT. This is the same site used prior to NTPEP's inception under the SASHTO Regional Testing Facility.
Besides flexible delineators, NTPEP conducts field performance tests on workzone drums/barrels, which are commonly used in construction and maintenance workzones to delineate and "separate" the travel way from the workzone. Typical application of workzone drums is in a taper approaching when workzone. AASHTO/NTPEP initiates testing on workzone drums only in the winter/summer test cycle (not summer/winter cycle); industry recommended this cycle because it represented a more severe endurance test.
The NTPEP Technical Committee responsible for authoring the Project Work Plan convenes yearly at the NTPEP National (Annual) Meeting. During this working meeting, the Project Work Plan is discussed, changes made, and shortly thereafter balloted for adoption. Improvements are immediately implemented in the next available testing cycle. When compared to other standards development exercises, the NTPEP process is agile, effective and efficient.