Gulf Power Highway 98 Infrastructure Case Study
American Electric Lighting fixtures help improve safety for drivers and pedestrians
Vehicle and pedestrian accidents sparked a Florida Department of Transportation (FDOT) safety audit for an unlit section of Highway 98 in Florida’s western panhandle. Audit results identified poor nighttime visibility as the cause of numerous crashes.
Based on audit findings, FDOT approached Gulf Power with the challenge of illuminating a 19-mile stretch of Highway 98 to boost pedestrian, bicyclist and driver safety. The section of highway is located in Santa Rosa County and is designated by the FDOT as a rural roadway.
“Highway 98 passes through various rural communities and—based on the region’s growth—includes a mix of rural, urban, commercial and residential areas,” said Kenneth Folsom, Gulf Power lighting services supervisor. “This is a busy section of highway with forty-five and fifty-five mile-per-hour speed limits and traffic counts exceeding forty-three thousand daily.”
Gulf Power presented the FDOT with several luminaire choices, including a high intensity discharge (HID) fixture, four LED luminaires and a plasma lighting product. FDOT selected three LED fixtures to field test. Based on Gulf Power and FDOT representatives’ observed performance of the tested fixtures, Gulf Power chose the Autobahn LED luminaires from American Electric Lighting. Maintenance was also a consideration.
Highway 98 is a four-lane divided highway with open ditches on the shoulders. Although the 19-mile stretch of roadway in Santa Rosa County was never illuminated in the past, Gulf Power had to mount the majority of the LED fixtures on existing wooden distribution poles. The poles are located along the right-of-way but offset 25 to 40 feet. Pole height ranges from 25 to 35 feet, with spacing varying greatly from less than 200 feet to 300 feet apart.
During the design phase, Folsom used a sample section of roadway he considered the worst case scenario in terms of pole spacing, set back and mounting height and created the lighting design to achieve a targeted 1 footcandle. “We believed that if we designed for the worst case situation, the LED fixtures would meet or exceed the one footcandle level we hoped to achieve along the entire stretch of highway,” Folsom said.
Gulf Power installed 991 Autobahn LED luminaires, mounting the majority of fixtures on existing poles. Where required, the utility installed new 40-foot wooden poles, mounting luminaires at 34 feet. Pole spacing averaged 200 feet on center. While the utility was not particularly concerned about light trespass, fixtures were tilted slightly or back shields installed in areas where trespass light proved an issue.
“The Autobahn luminaires perform very well—especially considering the mounting challenges we faced when designing the system,” Folsom said. “Florida Department of Transportation personnel and drivers alike appreciate the broad spectrum white light because it offers high levels of visibility. The LED system is also more energy efficient than HID luminaires, which is important to Gulf Power and the Florida Department of Transportation as we both emphasize energy responsibility.”
Fixtures are controlled by photocells and illuminated dusk to dawn. Gulf Power will maintain the luminaires and Folsom expects the fixtures to operate at least 10 years without requiring any real maintenance. The Autobahn LED fixtures’ light engine is rated for more than 100,000 hours at 40°C, with the electronic driver rated for 100,000 hours at 25°C.
“We’ve received many positive comments regarding the lighting,” Folsom said. “Roadway conditions are significantly improved and help create a safer environment for everyone who uses the highway, including drivers, pedestrians and bicyclists.”