Answer
Feb 26, 2026 - 05:22 PM
Spacing is determined by pole height, wattage, and photometric distribution. As a general planning rule, fixtures are spaced approximately 3 to 5 times the mounting height depending on the desired footcandle level. For example, at 20 feet high using a 150W or 300W fixture with Type 3 distribution, spacing may range between 60 and 80 feet for general parking illumination. Type 3 distribution produces an asymmetrical forward throw that helps extend pole spacing in roadway and parking configurations. Type 4 distribution is typically selected for perimeter lighting where forward throw with minimal backlight is required. Type 5 distribution produces a symmetrical square pattern and is often used in open parking lot layouts where poles are centrally located.
