1233f7edf64e51a5f938fbc38e467aff.ppt
- Количество слайдов: 20
AY WA M I N AD Y ODB R EDS E N L E P R T E NGO. T TI. H G LI S A L M A N /T . D
LIGHTING THE ROADS Roadway lighting is a proven safety countermeasure. The positive safety effects of lighting have been documented in various reports and publications. Source: FHWA Lighting Handbook August 2012. HID is the technology of the 60 s and LED is the future.
US DEPARTMENT OF ENERGY Of the numerous illumination platforms currently available, only Solid State Lighting-in the form of Light Emitting Diodes (LED)-offers our nation the potential to save energy and enhance the quality of our environment.
LED BENEFITS LED Benefits: - Decreased energy consumption & costs - Reduced maintenance costs; due to longer life - Visible commitments to efficiency - Improved safety through enhanced visibility - Decreased light trespassing and pollution - No mercury, lead, or other known hazards -Programmable controls/Dimming
DISADVANTAGES OF LED § § § Expensive initial cost …(but better life-cycle cost) Performance largely depends on ambient temperature & heatsinking (you can’t just stick an LED in a regular fixture housing) Light loss factors (LLFs) are not easily determined Must be supplied with the correct current (needs a power supply/driver to convert AC to DC) Because of their long life, they may not undergo the routine cleaning every 3 -5 years typically corresponding with re-lamping.
LUMINAIRE EFFICIENCY
LUMINAIRE EFFICIENCY TYPICAL 150 WATT HIGH PRESSURE SODIUM STREET LIGHT MEASUREMENT OF LUMENS REACHING THE GROUND TOTAL LUMEN OUTPUT OF HPS LAMP 22000 lm 100% DOWNWARD STREET SIDE DOWNWARD HOUSE SIDE DOWNWARD TOTAL LUMENS 6656 lm 6057 lm 12712 lm 30. 3% 27. 5% 57. 8% REFLECTOR INEFFICIENCY -9278 lm 42. 2%
LUMINAIRE EFFICIENCY
LUMINAIRE EFFICIENCY
PEDESTRIANS 5, 376 were killed and approximately 70, 000 injured in motor vehicle crashes on public roadways in the U. S in 2015. Pedestrians comprised about 15% of crash deaths. 12% of pedestrians were injured in a non-roadway location such as parking lot and therefore wouldn’t be counted in police-reported crash statistics (meaning it’s more than 70, 000). Source: Insurance Institute for Highway Safety and Highway Loss Data Institute.
LOCATIONS OF PEDESTRIANS CRASHES 54% of pedestrian deaths occurred in major roads and specifically at intersections (26%). Among pedestrian crashes of all severities, the most common scenario involves pedestrians crossing in front of a passenger vehicle that is traveling straight. These crashes typically occur on roads with speed limits below 40 mph, and about half occur at intersections.
HOW TO IMPROVE PEDESTRIAN SAFETY? Three main approaches: 1. Separating pedestrians from vehicles by time or space; 2. Making pedestrians easier to spot; 3. And reducing vehicle speeds.
USING LED FOR INTERSECTION LIGHTING • Contrast, is strongly correlated with quick identification of pedestrians and night-time crash reduction. • Higher vertical illumination results in better visibility in the cross walk.
USING LED FOR AREA PARKING
LED STREET LIGHT FIXTURES
LED POST LIGHT FIXTURES
LED HIGH MAST
LED IN TENNESSEE -The City of Knoxville: Largest LED Street Light Project in the State. Replacing: 29000 HPS/MV to LED. Final Cost: $13 million. Annual Energy Saving: $1, 054, 364. -AUB (Athens Utility Board): Complete conversion to LED by January 2017. (E-mail dated 4 -10 -17 from Alexa Voytek-Program Manager at TDEC) -Jim Kerr-Murfreesboro City-sent an e-mail to use LED lights for SR 268 (Thompson Lane): From Broad St. to Memorial Blvd -TDOT First Project: Interchange I-40 & SR-171 Mt. Juliet, Wilson Co.
LED STANDARDS AND SPECIFICATIONS Will be included in the updated version of TDOT Standard Specifications for Road and Bridge Construction (hopefully the 2018 Edition) & Traffic Operations Manual.
QUESTIONS / COMMENTS? !
1233f7edf64e51a5f938fbc38e467aff.ppt