A roadway's reflective characteristics are defined by its physical surface properties. Sufficient data has been collected on the reflectance characteristics of different pavement types to allow them to be described by reflectance tables or "R" tables. Several typical roadway pavements are provided for your use, as defined in the R-Table pull-down menu.
|
R-Table |
Q0 |
Description |
|---|---|---|
| C1 | 0.10 | CIE C1 - Concrete |
| C2 | 0.07 | CIE C2 - Asphalt |
| N1 | 0.10 | CIE Class = 1, Very Diffuse |
| N2 | 0.07 | CIE Class = 1, Concrete |
| N3 | 0.07 | CIE Class = 3, Asphalt |
| N4 | 0.08 | CIE Class = 4, Glossy Asphalt |
| NZN2 | 0.09 | New Zealand - Glossy Polished Asphaltic Surface |
| NZN4 | 0.09 | New Zealand - Diffuse Chip Seal Surface |
|
R1 |
0.10 |
IES RP-8 - Mostly diffuse reflectance properties characteristic of Portland cement or asphalt surface with a minimum of 15% of the aggregates composed of artificial brightener aggregates. |
|
R2 |
0.07 |
IES RP-8 - A combination of diffuse and specular reflectances characteristic of asphalt surfaces with aggregate composed of a minimum of 60% gravel of size greater than 10 mm. Also asphalt surfaces composed of 10% - 15% artificial brightener in aggregate mix. |
|
R3 |
0.07 |
IES RP-8 - Slightly specular reflectance typical of asphalt surfaces with dark aggregates, rough texture and some months of use. This surface is common in the United States. |
|
R4 |
0.08 |
IES RP-8 - Mostly specular surface typical of very smooth asphalt texture. |
| UKPA |
0.05 |
UK - Porous Asphalt |
| W1 | 0.11 | CIE W1 - Wet Road Surface |
| W2 | 0.15 | CIE W2 - Wet Road Surface |
| W3 | 0.21 | CIE W3 - Wet Road Surface |
| W4 | 0.25 | CIE W4 - Wet Road Surface |
|
ZOAB |
0.10 |
CIE Class = 2, Dutch Porous Asphalt |
Q0 is a value that is related to the overall reflectance of the pavement by a factor of π: Q0 x π = overall reflectance.
Additional R-tables can be added to AGi32 easily. Please contact Lighting Analysts for details.
Note: If a user creates an R-Table and then uses it in an AGi32 calculation, that R-Table is not included with the saved AGI file. Therefore, if that AGI file is transferred to another computer, AGi32 will not find the custom R-Table and will use the default (R3). The custom R-Table would have to be added to the new computer in the ProgramData folder manually.