The work done to date on airport runways, taxiways and high-speed turn-offs, plus the preliminary work on roadways and on model studies in the fog chamber, demonstrates the versatility and utility of the principle of lineal guidance obtained by light sources inset into pavement surfaces. The principle of guidance as now proposed is generally accepted for airport use. It is hoped that the next step will be to apply the principle to some of the more critical areas on roadways. This is being considered, and some tests have been made by the connecticut department of highways in conjunction with one of the leading lighting equipment manufacturing companies. Another trial installation has been proposed for the golden gate bridge at san francisco. This installation would be a combination lane-marking system and center-lane reversal system. The operation would be accomplished by shifting the double line from the center to one lane each side of center, using lighted lights on suitable switching circuits. The extra-visual information provided by lighted lane-lines under good visibility conditions is a desirable feature. This means of providing added visual information under poor visibility conditions is highly desirable. Under poor visibility conditions the range of visibility of lighted lane-lines is far greater than with any of the present paint markings or border materials. In general, the visual range can be approximately doubled, using lighted lights, over that which is available using reflective-type marking materials. The low-wattage units placed on close spacing have been found to be preferable to higher-wattage units placed on wider spacings. One reason for this is that the continuity of the lineal pattern is improved and the glare per individual unit is greatly reduced. It is hoped that several trial installations of lighted lane markers can be made on actual roadway locations in the near future, so that the usefulness and versatility of the system can be proved in actual trials.
Abstract