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<br /> <br />Mo-DOT Engineering Policy Guide (MoDOT, 2011) <br />Although the MoDOT Engineering Policy Guide refers mostly to freeways, much <br />for the development of a new street light policy. Some of which <br />HPS lamps are used for fixed source lighting of roadways and und-watt lamps are rated <br /> <br />at 16,000 lumens, 250-watt lamps are rated at 27,500 lumens, and 400-watt lamps are rated at 50,000 <br />lumens. <br />Continuous lighting installations along freeways, urban arterial <br /> <br />thereto must provide an average maintained intensity of 0.6 fc ( <br />fc (2.2 lux). Continuous lighting installations on existing roadways, not including freeways, urban <br />arterials, expressways or ramp connections thereto must provide <br />0.4 fc (4.3 lux) and a minimum intensity of 0.2 fc (2.2 lux). <br />Basic lighting at intersections, including ramp terminals at crossroads, is to provide an average <br /> <br />maintained intensity of 0.6 fc (6.5 lux) and a minimum intensity <br />intersection. <br />Luminaires are to be positioned within 3 ft. at the 30-ft. mounting height and 5 ft. at the 45-ft. mounting <br /> <br />height from the edge of the nearest traffic lane. This applies t <br />lighting. <br />The following calculation is given to determine footcandles/spacing for luminaires: <br /> <br /> <br />Avg = <br /> <br /> <br /> <br />Where: <br /> <br />Avg. = Average footcandles or Average lux <br /> <br />Lamp Lumens = Initial lamp lumen rating <br /> <br />Utiliz. Coef. = Coefficient of Utilization <br /> <br />Maint. Factor = 0.70 <br /> <br />Spacing = either ft. (for fc) or m (for lux) <br /> <br />Width = Roadway width, either ft. (for fc) or m (for lux) <br /> <br /> <br />The table below lists typical continuous lighting designs for di <br />combinations. Various brands of luminaires perform slightly diff <br /> <br /> <br /> <br /> <br /> <br /> <br />40 <br />Page <br /> <br />