(4) In the event it is found not to be practical to measure a changeable message sign at the distances prescribed in subdivision (h)(2), a measurer may opt to measure the sign at any of the alternative measuring distances described in the applicable table set forth in this subdivision (h)(4). In the event the sign measurer chooses to measure the sign using an alternative measuring distance, the prescribed foot candle level above ambient light must not exceed the prescribed level, to be determined based on the alternative measuring distances set forth in the tables in subdivisions (h)(4)(A), (B), (C), and (D), as applicable. For any measuring distance between the alternative measuring distances set forth in the following tables, the prescribed foot candle level above ambient light must not exceed the interpolated level derived from the following formula: [l2 = (D2<2>/D1<2>) x l1]
Where l1 = the prescribed foot candle level above ambient light for the measuring distance listed in the tables, l2 = the derived foot candle level above ambient light for the desired measuring distance, D1 = the desired measuring distance in feet, and D2 = the alternative measuring distance in feet listed in the tables, as follows:
(A) For changeable message signs less than or equal to three hundred square feet (300 sq. ft.): Alternative Measuring Distance: | Prescribed Foot Candle Level: |
100 | 0.68 |
125 | 0.43 |
150 | 0.3 |
200 | 0.17 |
250 | 0.11 |
275 | 0.09 |
300 | 0.08 |
325 | 0.06 |
350 | 0.06 |
400 | 0.04 |
(B) For changeable message signs greater than three hundred square feet (300 sq. ft.) but less than or equal to three hundred eighty-five square feet (385 sq. ft.): Alternative Measuring Distance: | Prescribed Foot Candle Level: |
100 | 1.2 |
125 | 0.77 |
150 | 0.53 |
200 | 0.3 |
250 | 0.19 |
275 | 0.16 |
300 | 0.13 |
325 | 0.11 |
350 | 0.1 |
400 | 0.08 |
(C) For changeable message signs greater than three hundred eighty-five square feet (385 sq. ft.) but less than or equal to six hundred eighty square feet (680 sq. ft.): Alternative Measuring Distance: | Prescribed Foot Candle Level: |
100 | 1.88 |
125 | 1.2 |
150 | 0.83 |
200 | 0.47 |
250 | 0.3 |
275 | 0.25 |
300 | 0.21 |
325 | 0.18 |
350 | 0.15 |
400 | 0.12 |
(D) For changeable message signs greater than six hundred eighty square feet (680 sq. ft.): Alternative Measuring Distance: | Prescribed Foot Candle Level: |
100 | 3.675 |
125 | 2.35 |
150 | 1.63 |
200 | 0.92 |
250 | 0.59 |
275 | 0.49 |
300 | 0.41 |
325 | 0.35 |
350 | 0.3 |
400 | 0.23 |
425 | 0.2 |
450 | 0.18 |
500 | 0.15 |