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CAASD has been conducting research on an innovative runway marking project that it created to help pilots and others operating vehicles on airport surfaces see critical "Hold Short" markings better. Painted on airport taxiways, these visual markings indicate areas at controlled airports that can not be crossed--the pilot must "hold short" of the marking--without prior permission from air traffic control.

Airport surface markings and signage are important aids to help aircraft and vehicle operators navigate the airport surface and to communicate their location to air traffic controllers. The increased conspicuity of these new markings might contribute to the reduction of runway incursions, which occur when aircraft on the ground that are holding, taxiing, landing or taking-off come in danger of colliding with other aircraft or vehicles.

Over the past few years, runway incursions have emerged as a major safety issue in aviation. The worst aviation accident in history---the crash of two Boeing 747s on Tenerife in 1977 that claimed 863 lives¿was the result of a runway incursion. The National Transportation Safety Board¿s current list of its "Ten Most Wanted" transportation safety improvements includes the Reduction of Runway Incursions by providing for safer control of aircraft on the ground.

While there are many contributing causes to runway incursions, surface marking continues to be cited as one leading factor. For example, in April 2000, a popular aviation Web site, AvWeb, posed as its "Question of the Week," What can be done to reduce runway incursions? The largest percentage of respondents identified airport signs and markings as a key factor.

The CAASD project utilizes three-dimensional artistic techniques to make airport surface markings more conspicuous to pilots and vehicle operators on the airport surface. The technique CAASD has employed, based on anamorphic projection is one that artists have used since the Renaissance. In essence, this technique creates the illusion that an object is three-dimensional rather than two-dimensional. This project is intended to determine whether the new marker can be more effective in alerting pilots to the "hold-short" indication. It has already caught the eye of the aviation community, with articles appearing in the Aircraft Owners and Pilots Association¿s (AOPA¿s) e-Pilot and the Air Line Pilots Association¿s Airline Pilot magazine.

The specific surface marking is a runway holding position (hold short line) marking painted on the ramp adjacent to AOPA¿s headquarters at the Frederick, MD, airport. The project was internally funded through the MITRE Technology Program in cooperation with the AOPA. MITRE is working with the FAA¿s William J. Hughes Technical Center at Atlantic City, NJ, to pursue next steps in evaluation this concept.

Runway Surface Markings and Runway Incursions

Runway holding position markings, commonly referred to as "runway hold lines" or "hold short lines," are one of several important aids that assist pilots and vehicle operators as they navigate on the airport surface. Painted on taxiways, and sometimes on intersecting runways, these markings indicate a boundary which may not be crossed without prior air traffic control (ATC) authorization. The failure to visually acquire a runway holding position marking early enough to avoid crossing or encroaching upon it is a known contributor to runway incursions.

Runway incursions represent a serious and growing hazard affecting the safety of operations at United States airports. Defined by the FAA as "any occurrence at an airport involving an aircraft, vehicle, person, or object on the ground that creates a collision hazard or results in loss of separation with an aircraft taking off, intending to takeoff, landing, or intending to land," runway incursions have become a major concern to aviation safety experts. The total number of runway incursions at U.S. airports increased every year from 1993 to 1998, and then decreased slightly in 1999.

While not especially prominent in the public¿s mind as a major safety hazard, runway incursions have migrated from the occasional terror nearly all pilots face at one time or another to a top priority for the FAA. The need to address the issue now is driven, in part, by the steady growth of civil aviation throughout the world, and in part because runway incursions have increased over the past decade, in spite of the FAA¿s efforts to reduce them. As the number of flight operations continues to climb, a reduction in incursion rates will be necessary if the number of incidents is to be kept under control in the future. To achieve this goal, the aviation industry is looking at a range of technical and procedural solutions. In June 2000, the FAA hosted a three-day Runway Safety National Summit in Washington, DC to address the steady rise in runway incursions. As FAA Administrator Jane Garvey said, "We know that taxiing on the airport surface is the most hazardous phase of flight."

While there are many contributing causes to runway incursions, surface markings continue to be cited as a leading factor. In recommendations taken from the June Summit, the FAA listed ten major steps that needed to be taken immediately, one of which involved airport markings. Specifically, the FAA suggested the need to increase the visibility of hold lines by increasing the width of the yellow bars from 6 to 12 inches and by painting a hold short lines on a black background. This step, beginning in mid-August, is scheduled for completion by Dec. 31, 2000.

The Birth of an Idea

The inspiration for this research came from the "Community Bridge" project, in Frederick, MD, in which similar techniques were employed by the artist William M. Cochran to give a three-dimensional look and feel to an otherwise "normal" concrete bridge (http://bridge.skyline.net/). While viewing the Cochran¿s art work on the "Community Bridge," a MITRE employee who had been an air traffic controller was particularly impressed by one of the muralist¿s portraits.

This was the figure of the Archangel, which when viewed straight on looked distorted, but became clearer as the viewing angle became more acute. He envisioned the possibility of this technique being used to enhance airport surface marking conspicuity. MITRE contracted with the artist to help apply these techniques to a runway holding position marking. The initial application of this "anamorphic projection" technique on a scaled model produced a striking result that led to discussions with AOPA and the application of the marking on the AOPA aircraft parking ramp.

The first version of the runway holding position marking conformed to FAA size specifications for airport markings, and did produce a 3-D effect. However, the project team determined that a greater visual impact could be achieved by making the marking bigger. While this second image was larger than prescribed by current FAA specifications, it appeared to have the potential to provide significant benefits in enhanced conspicuity and earlier visual acquisition. FAA specs have been waived or altered in the past to accomp-lish specific goals. In fact, the FAA¿s list of "Ten Near-Term Initiatives" for Runway Safety includes an initiative for changing AC 150/5340-1H (Standards for Airport Markings) to specify standards for double-sized markings, outlined in black, on all runway hold lines at certificated and towered airports.

Next Steps

Having a full-scale prototype of the marking available for viewing in an actual airport environment has provided an invaluable opportunity to collect informal feedback and to make some preliminary assessments of the marking¿s potential. The next logical step would be to place prototype markings on operational taxiways at selected field locations. Accordingly, CAASD is working to transfer information on the prototype to the FAA¿s William J. Hughes Technical Center in Atlantic City, NJ, for consideration in their safety research programs.

Date Posted: July 28, 2004