Discussion of Work Plan

The brightness readings required in the Sight test (2.1) for the Arrowboard and PCMS work plans were taken with an AEMC model 814 light meter. The light meter was placed against the lens or the lens cover of the Arrowboard and PCMS to get the light meter as close to the light source as possible. The same light meter was used in the Durability test (3.3) for both devices. Appendix E shows the position of the light while taking the readings for PCMS and Arrowboards.

No area with close proximity to Raleigh could be found to meet the requirements of Table 1 in the Visibility test (2.3) of the Arrowboard work plan for Type "C" arrowboards. The team recorded the distance at which the arrowboards were visible and believe that all arrowboards tested in this test cycle exceeded the Manual on Uniform Traffic Control Devices requirement of 1 mile.

The Angularity test (2.5) for both devices was performed using field engineering judgement. No surveying instruments were used to determine this angle as they were not practical in this application.

The Sight tests (2.3, 2.4, 2.5) for both the Arrowboards and PCMS were performed with all the devices in the test cycle placed side by side a minimum of 20 feet apart at the east end of Runway 9-27 (see Appendix C ). All three tests for Arrowboards and PCMS were performed using a 1998 Plymouth Breeze sedan in good condition. While the Angularity tests (2.5) were performed from the drivers seat by all four evaluators, the Visibility tests (2.3) and the Legibility tests (2.4) were performed with all the evaluators seated in the vehicle at once as each sign was reviewed. This was done for tests 2.3 and 2.4 because of the time consuming nature of these tests. Some thin high clouds were present during the sight tests.

As stated earlier, the work plan was developed by a task force which reviewed a large number of member agency specifications. Several State Highway Agencies require solar-powered Arrowboards and PCMS to run with their solar panels disconnected from the batteries they replenish. It was decided by the task force to create test 3.2.2 in the work plan to measure this reliability feature of the devices. In several cases this required breaking solder joints to disconnect the battery banks from the power source. It became obvious to the testing team that accidental solar power disconnect had become a problem in the day to day operation of the devices and many manufacturers had dealt with that in a very positive way by making it difficult or impossible to accidentally disconnect the power source.

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