| When two children were injured while crossing Mayfield Avenue at Red Barn Way in Howard County, Maryland, Ed Walter (retired) decided it was time to do something different.
As Chief of the Traffic Engineering Division of Howard County, Walter knew that pedestrian injuries are approaching epidemic proportions - nearly 6,000 deaths and 110,000 injuries in the U.S. each year. He also realized that this particular school crossing had the potential for a recurrence. Mayfield Avenue's wide, straight approach to Red Barn Way was an invitation to thoughtless driving.
|
A push button at either end of the crosswalk activates six high intensity yellow lights that flash once per second for 30 seconds. The staggered placement of TS230 fixtures maximizes visibility.
|
| At a time when some jurisdictions are removing crosswalks to avoid litigation, Walter chose to take a pro-active approach. Unfortunately, the $80,000 cost of a traffic signal was prohibitive, and installation at this location did not meet national warrants. Walter thought that inpavement lights could alert motorists when pedestrians were in the crosswalk and might be a lot cheaper.
But what kind of light can survive the pounding of heavy traffic? He knew that inpavement fixtures had to be tough enough to withstand repeated impacts by large vehicles, so he placed a call to Traffic Safety Corp. (TSC), in Sacramento, California.
Traffic Safety Corp. manufactures and distributes an extensive line of traffic safety equipment. Inpavement lights are frequently used in Europe at crosswalks, round-abouts and high volume docks such as Felixstowe in England. Because these fixtures have a proven track record, TSC recently began offering them for crosswalks and lane control in the U.S.
Traffic Safety Corp. suggested that Walter select a ZA200 Series high intensity, bidirectional light. The TS230 is installed around the world - from London and Hong Kong to Washington D.C. and San Francisco. Its projection above grade is only 0.39", which allows snow plow blades to pass harmlessly over the fixture and does not hinder bicyclists. The fixture is 8" in diameter and is set in an underground canister of galvanized steel. It is designed to withstand a dynamic load of 11 tons.
Walter chose 45 watt lamps and yellow lenses to project bright beams in both directions (30 watt lamps and clear and red lenses were also considered). The lights are activated by pedestrian push buttons at the curbs and flash once per second for 30 seconds.
Before the lights were installed, Walter had the parking lanes choked off at the approach to the crosswalk. This had the effect of reducing the speed of approaching vehicles, cutting the number of fixtures required and limiting the time pedestrians were in the crosswalk.
|
The TS230 is only 8" in diameter and will withstand a dynamic load of eleven tons. The fixture slopes from 0 - .39" above the roadway, so that bicycles and snow plow blades ride over it without hindrance. The caution-yellow light flashes in both directions.
According to Walter, installation was a quick, straightforward process, except that conduit and cable had to be run 300 feet from the crosswalk to a power source.
Six 10" holes were core drilled in the street, 4" deep, three on each side of the crosswalk, and saw cuts were made in the pavement to accommodate electrical lines between the fixtures. Base cans were then installed using flat metal leveling bars bolted through temporary plywood covers on the cans. These cans feature a bottom rim to prevent uplift and anti-rotation fins to avoid lateral shifting over time.
The cans are held in place by Traffic Loop Sealant (epoxy) which cures in about four hours or Quick Dry Cement (HD50) which drys in 20 minutes, after which the jigs and the protective plywood covers were removed and the TS230 fixtures bolted in place with vandal-proof hardware.
Walter has received positive responses from both motorists and pedestrians and is currently gathering traffic speed data on the installation. As for cost, Walter said, "materials and labor brought the total cost to approximately10% of what a traffic signal would have cost, and we think it will prove to be more effective - especially since we could afford to do the job immediately, before another child got hurt."
California's Traffic Control Device Committee recently endorsed inpavement lights for crosswalks. Readers having questions should call Traffic Safety Corp., at 1-888-446-9255.
|
