Detection of Work Zone Traffic Control Devices

This paper reviews recent research on the visibility of and driver reaction to various work zone traffic control devices. The greatest problem with advance signing is credibility, since the work zone situation will frequently change after the sign is erected. The recognition distance of arrow boards is between 725-1175 feet, depending on speed. They are most useful for lane closures by promoting earlier merging. Only in specific situations are they useful for lane diversion. A study of concrete barrier visibility focused heavily on the durability of six reflective products over two years. From a visibility perspective, reflectors were superior to reflectorized tape. A study of cones, tubes, barricades, panels, drains, and steady burn lights indicates relatively successful detection and path guidance performance by most devices. One of the major deterrents to effectiveness is not the device, but the position, dirty, or overturned devices destroy the visual line or path created by channelizing devices. Therefore, use of appropriate devices is important but diligent set-up and care of the work zone is equally important.”