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<br />In addition to the initial capital investment of installing the streetlights, long-term <br />maintenance and operation costs should also be considered. Maintenance and operations <br />costs would be proportionally (per light) more expensive for the more intensive lighting <br />approach. <br />Design Standards/Justification for Proposed Code Amendment: <br />Roundabout Lighting: MnDOT and FHWA design guidance recommends that all <br />roundabouts be lit to provide adequate visibility for all modes of transportation during non- <br />daylight hours. This guidance is consistent with past precedence for roundabouts <br />constructed by Ramsey County and the City of Arden Hills. <br />Vehicular Lighting: Street lighting is designed based on various physical factors of the <br />lighting pole, trajectory, and luminaire intensity. The City of Arden Hills Public Works Design <br />Manual (Draft) specifies the light type and design parameter for the lighting to be installed <br />along Rice Creek Boulevard. Application of MnDOT photometrics design guidance, the <br />specified lighting units would result in recommended spacing of approximately 200-ft. <br />Detailed design of the lighting system would prioritize light locations at intersections and <br />pedestrian crossings which reduce the space between lights in those locations. The <br />following information is attached to this memo in the appendices providing further detail of <br />the vehicular lighting design: <br /> Appendix A: Photometric layouts for 40-ft vehicular lighting per current TRC code. <br /> Appendix B: Photometric layouts for the proposed vehicular lighting meeting <br />standards established in the MnDOT Roadway Lighting Design Manual. <br />The table below summarizes the design criteria of the MnDOT Roadway Lighting Design <br />Manual and the performance of each of the two options against the standards. <br />Design Alternative Minimum Avg <br />Illuminance <br />(Fc) <br />Design Avg <br />Illuminance <br />(Fc) <br />Minimum <br />Uniformity <br />(Avg/Min) <br />Design <br />Uniformity <br />(Avg/Min) <br />40-ft Light Spacing (Current TRC) 1.0 7.32-8.11 4.0 1.29-1.44 <br />Proposed Light Spacing (MnDOT) 1.0 1.05-1.20 4.0 3.0-3.5 <br /> <br />Local Area Precedence (Vehicular Lighting): The following corridors/intersections have been <br />constructed with streetlighting within the project vicinity. Design parameters for those <br />systems are provided for reference. <br /> Rice Creek Parkway (County Road I to County Road J) <br /> Light Type Comparison: Shorter, more decorative luminaire <br /> Light Spacing: Approximately 200 feet <br /> Speed Limit: 30 mph <br /> Snelling Avenue/County Road E Roundabout <br /> Light Type Comparison: Similar height and luminaire <br /> Light Spacing: Lights at all intersection quadrants, 140-200 feet exiting RAB <br /> Speed Limit: 25-35 mph, 45 mph north on Snelling Ave <br />