Transit Cooperative Research Program Sponsored by the Federal Transit Administration RESEARCH RESULTS DIGEST July 1996--Number 9

Subject Area: VI Public Transit Responsible Senior Program Officer: Christopher W. Jenks

Responding to Vandalism of Transit Bus and Rail Vehicle Passenger Windows

This TCRP digest provides a summary of findings from TCRP Project C-4, "Enhancement of Vehicle Window Glazing for Vandal Resistance and Durability," conducted by the University of Dayton Research Institute. Included in the digest are brief descriptions of current and emerging methods available to address the passenger window vandalism problem.

INTRODUCTION surveillance, and other technologies. Service life and maintenance issues are a function of the procured Transit vehicle windows have become high system and the operating environment. Strategies to profile items because of problems with vandalism improve service life and reduce maintenance and related maintenance. Whereas the window used problems have implications for new procurements in to last the life of the vehicle or was changed-out only terms of specifications for durable, relatively trouble- on that rare occasion when it was chipped or broken, free, vandalism-resistant technologies. it has now become a consumable item requiring Under TCRP Project C-4, research was frequent change-outs, considerable maintenance undertaken by the University of Dayton Research resources, and the logistics of maintaining an Institute to (1) compile information on transit bus and inventory of spares. In New York City alone, the rail vehicle window vandalism and current and MTA New York City Transit reports that properly emerging window glazing technologies with potential maintaining vandal-etched bus and rail windows applicability to the transit industry and (2) develop costs $60-70 million annually. In addition, surveys guidelines to assist transit agencies in the preparation indicate that the cost of vandalism for mass transit is of procurement specifications related to transit bus increasing by 11 percent per year, which means that and rail vehicle passenger windows. it is doubling every 6.5 years. This rise in vandalism Three documents were produced from the has caused many transit agencies to rethink windows project: (1) TCRP Report 15, "Procurement and window issues. Vandal resistance and quick Specification Guidelines for Mass Transit Vehicle change-out of the windows are becoming high Window Glazing," prepared for transit maintenance priorities to transit agencies with vandalism and procurement specialists concerned with the problems. development of specifications for the purchase of There are essentially three ways to attack the durable and vandal-resistant bus or rail vehicle vandalism problem: (1) the development of repair passenger windows and window systems; (2) an techniques for the current system, (2) material unpublished final report, "Enhancement of Window solutions to the problem, i.e., materials or material Glazing for Vandal Resistance and Durability," systems that provide resistance to vandalism, and (3) which provides the details of extensive surveys prevention. Prevention includes police/security, conducted during the project of domestic and foreign maintenance, and operator involvement, as well as transit systems, window transit authority policies, punishment, legislation,

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TRANSPORTATION RESEARCH BOARD NATIONAL RESEARCH COUNCIL 2 system manufacturers and suppliers transportation systems vehicles like afford to spend the "one dollar required serving transit and other industries, railroad cars and semi trailers. Since a to save one hundred dollars." transit vehicle manufacturers, and desire for recognition is inherent in the There are two distinct groups that vandalism and graffiti experts; and (3) act of vandalism, permanence of the have minimal or no problems with this Research Results Digest, which graffiti or other damage is of prime window vandalism. The first group is provides a brief summary for transit importance. Glass and plastic windows, located in areas where the "fad" has not managers of the information contained enclosures, and mirrors provide durable become popular. The second group is in the final report. Copies of TCRP canvases for the "artwork." Windows in in areas where, though graffiti and Report 15 and the project final report particular (they cannot be repainted, are vandalism are high, anti-graffiti are available through the TCRP, 2101 not easily resurfaced in situ, and are measures (maintenance, security, and Constitution Avenue, N.W., costly to replace) invite graffiti. driver practices) discourage and control Washington, DC 20418. Vandals use a number of objects it. Also, there is a variation in severity to scratch, scribe, etch, cut, scuff, or of the vandalism problem within a VANDALISM AND GRAFFITI deface transparent materials, and given agency between the various ground transportation vehicles sustain modes of transit. Commuter rail Vandalism has become damage ranging from breakage of the systems are often relatively free of increasingly present and visible in the window panels to scratches and scuffs damage, while other modes of transit in public sector over the past 35 years. to elaborate drawings or messages. the same area are not. This is often Graffiti is the main form of defacement These messages may be written in strictly a function of the ridership. to publicly owned property. The English or encrypted with special Commuters tend to be older, more national cost of property removal and characters that are intelligible only to responsible citizens. The other transit replacement due to vandalism and persons "in the know." These groups modes which carry school-age children graffiti exceeded 7 billion dollars in have underground publications that and young adults are more likely to 1994; more than 1 billion dollars was encourage, interpret, and teach this sustain damage. Buses and trolleys are spent to remedy glass etching. vandalism. The Internet is also being easy targets for vandals because stops Over the past 3 years, vandalism used to spread information on the best are frequent and security is less than on in the form of scratching, scribing, and places to "hit" and the tools to use. other transit modes. etching windows has become a Some prestigious universities even problem for most transit authorities; for offer courses in "Graffiti Art." TRANSIT WINDOW some it has grown to epic proportions. Vandalism of windows in ground MAINTENANCE AND Unlike spray paint and marker graffiti, transportation vehicles was ENGINEERING ISSUES window scratching and etching cause concentrated mostly in large permanent damage and cannot be metropolitan areas, but now has spread Window system issues dealing cleaned with a solvent or repainted. to smaller cities nationwide. with graffiti include the need for easily Glass window etching and scratching procured replacements and easy can compromise the structural integrity RESULTS OF TRANSIT SURVEY maintenance, especially quick change- of the window, reducing its resistance out of windows. Transit maintenance to impact and increasing the potential Problems with durability and staffs, already overburdened with spare for passenger injury. vandalism/etching of the windows vary vehicle shortages and the work required In this project, vandalism and widely among the transit systems. to keep vehicles fueled and operating, graffiti are considered in several forms. Some transit systems describe the have little time remaining to take on These include defacement, "artwork," condition of their windows as a disaster special tasks like window maintenance messages, and tagging. The last three with a very high percentage currently and change-out. Prior to the surge in contain elements of self- etched or damaged and a very high graffiti problems of the past few years, recognition/public recognition. Targets graffiti/ vandalism/etching rate (in windows were changed only when they for vandalism have included exterior terms of incidents per day or week). "wore out." Many window designs are structures such as signs, buildings, Some systems report almost no not conducive to maintenance and walls, and bridges; interior structures problems. Overall, problems with quick change-out. Curved window such as malls, elevators, and escalators; window etching are increasing panes, while aesthetically pleasing, elements of the public transportation throughout the transit community. Of have a number of inherent system such as buses and light rail the systems with major problems, some disadvantages including increased cost transport systems; and other realize what should be done to fix the and limited procurement sources. Flat problems, but cannot windows,on

These Digests are issued in the interest of providing an early awareness of the research results emanating from projects in the TCRP. By making these results known as they are developed, it is hoped that the potential users of the research findings will be encouraged toward their early implementation. Persons wanting to pursue the project subject matter in greater depth may do so through contact with the Cooperative Research Programs Staff, Transportation Research Board, 2101 Constitution Ave, N.W., Washington, DC 20418. 3 the other hand, are less expensive, are when broken). Acrylic is subject to returned to the transit authority. There widely available, and can be changed hazing and crazing, it burns, and it are a number of logistical relatively easily between window requires a protective coating. complications relating to material systems. Most transit and Polycarbonate provides superior refurbishment, which include record maintenance personnel indicated that impact resistance but its softness is keeping, storage, and shipping. There they would not procure new vehicles susceptible to abrasion and scratching, are significant savings, however. One with curved windows. as well as environmental and chemical system reported paying $240 to have Typical change-out time for most attack, and it must have a protective acrylic bus windows (which cost $1000 vehicles, including rail cars with the coating. new) refurbished. The pressures of rubber gasket "zip-strip" edge designs, All of these materials, glass, refurbishment and competition have is half an hour or more. This results in acrylic, and polycarbonate are less resulted in significant reductions in the significant additional maintenance time expensive in the flat condition. cost of new acrylic transparencies. This when a number of windows require Forming them into shapes or curvatures reduction of the margin in cost between changing on a night shift; this hits a increases the window cost. new and refurbished windows has transit system with a "zero tolerance/no Durability of plastic materials is a reduced the attractiveness of vehicle in service with graffiti" function of the type of plastic or refurbishment for some agencies. standard particularly hard. coating system and the environment to Of the three window types which the window is exposed. Plastic Sacrificial Plies and Films-- currently available, fixed windows are ages and degrades from the effects of Several relatively new vandalism- the most attractive from a maintenance time, temperature, moisture, and resistant material solutions are standpoint, followed by transom ultraviolet light. Other aging factors immediately available and are currently windows, and sliding windows. include pollution; chemicals used on or being evaluated and/or procured by Transom windows have been chosen as in the vicinity of the windows various transit agencies. One of these is a compromise by many agencies for (cleaners, graffiti removers, solvents, a sacrificial ply system which is an although they are more complex than fuel, etc.); abrasion from cleaning; inexpensive piece of plastic held to the fixed windows, they are less prone to scratching from cleaning or with window's interior side with two-sided failure than sliding windows. foliage, signs, etc., while in motion; tape, or is held in place by the window and impact damage and vandalism frame itself. These plies can be (etching, scratching, and carving). The replaced quickly after being MATERIAL SOLUTIONS use of brush washing systems and vandalized. A stock of die-cut graffiti removal substances may affect sacrificial ply panels can be kept on the durability of plastic transit hand for quick change-out. A $10 to Background--There is no windows. To illustrate the negative $15 cost per replacement is reported, consensus among transit authorities on effects of environmental conditions, at and change-out time can be as short as which existing transparent material one transit system, hardcoated acrylic 5 min. A second vandalism-resistant systems is the best. For certain modes bus windows last approximately 2 material solution is a peel-ply of transit, the material system is years before they are severely crazed protective film placed over the interior dictated by regulations. Existing (i.e., a crack-like surface phenomenon of the window. When this peel-ply is transparent window materials in use in plastics). The same acrylic bus damaged, it is stripped off and include safety glass, coated acrylic, and windows used by a number of other replaced. Peel-ply products are also coated polycarbonate. systems virtually never craze. What are inexpensive, but do not change-out as Glass provides superior service the differences? Climatic conditions quickly as the sacrificial ply products. life and is impervious to chemical (temperature, moisture, and UV A stock of die cut, peel-ply sacrificial attack, aging, and environment. dosage), air pollution, bus washing films can be maintained for quick Moreover, glass is the most difficult fluids, and the frequent use of graffiti change-out. A $5 to $10 cost per material to scratch. But its drawbacks removal substances all take their toll. replacement is reported, and change- are that it is heavy, cannot be out time can be as short as 15 min. refurbished easily, and has higher However, vandals have been known to liability because of flying glass when a Refurbishment--Another method lift the peel-ply and scratch or etch the window breaks. under evaluation is window substrate. Acrylic can be refurbished refurbishment. To date, this has only (ground, polished, and recoated) but it been economical on acrylic windows. Anti-Spall Technologies--Anti-spall does not provide the impact protection The acrylic windows are removed from films have been developed specifically of laminated safety glass or service, ground, polished, and recoated to combat "smash and grab" robberies, polycarbonate (acrylic fractures into at a refurbishment/repair facility, and car-jacking, and hurricanes. They are large jagged pieces applied to the interior surface of glass 4

windows to prevent glass spall when abrasion resistance, chemical change-out, these window systems may the window is damaged and are already resistance, thermal resistance, and require items such as dry seals on the being used by a number of transit durability. This technology has not yet outboard side of the window and a systems. The impetus to use the been evaluated for use in transit clamped interior frame, which is product is to reduce the possibility of systems. removed easily after removal of a passenger injury resulting from spalled number of specialty head (e.g., Torx) (flying) glass. In some cases, the PREVENTIVE SOLUTIONS quarter-turn fasteners. These window relatively soft anti-spall film is further systems for new procurements should protected from carving and etching by a Survey findings indicate that the specify provisions for sacrificial ply sacrificial acrylic ply. one system which controls vandalism is protection (peel-ply protection does not an integrated team approach to zero require any special provisions since it Coating and Aerospace tolerance. Zero tolerance means "no does not require its own frame). The Transparency Technologies--A vehicle in service with graffiti." The least complex window systems are number of technologies that have been integrated team includes drivers, preferable, such as fixed windows. developed for the aerospace industry security, maintenance personnel, and Transom windows are more complex, have application to transit system may even include the passengers. This and sliding windows are the most windows. For example, polyurethane zero tolerance approach should be a complex and the most troublesome. coatings and liners have been structured proactive cooperative effort. The window frames should be clear developed that increase the durability Practices of this zero tolerance anodized aluminum or stainless steel. of plastic transparencies. These new team may include anti-graffiti Black anodized aluminum has proven materials are significantly more education, immediate reporting of to be a target for carvers because of its resistant to scratching, scuffing, problems, immediate response to high contrast qualities when carved. abrasion, chemical attack, and problems, routine and random Additional in-depth treatment of future weathering than uncoated plastics. uniformed and undercover patrols, procurements is addressed in TCRP Polyurethane liners have self-healing video surveillance, rewards and Report 15, "Procurement Specification properties (gouges and imprints and bounties, truancy sweeps, Guidelines for Mass Transit Vehicle abrasion damage disappear with time documentation of incidents, inter- Window Glazing." and/or with the application of heat). agency sharing of tag documentation The aerospace industry has also and tagger files, prosecution of all conducted significant research over the vandals (treatment of vandalism as a CONCLUSIONS AND past several years to combat chemical crime), punishment including arrest and RECOMMENDED RESEARCH crazing of acrylic airline cabin side detainment as well as vandal and windows. A number of advanced parental monetary fines and coatings are being flight tested, but no responsibility for damages, and There is no known material that is concrete data is available to indicate immediate cleanup/repair of vandalism/ impervious to vandalism. Glass is more which coatings provide the best service damage (within 24 hours or less). difficult to scratch than plastics and has life. Customer respect is an important issue. superior durability, but it is subject to Another concept that is being A clean, presentable, and comfortable damage when attacked with hard evaluated by the aerospace industry is system fosters customer respect and the objects (carbide-tipped scribes, rocks, an acrylic side window clad with a very teamwork that produces it strengthens gemstones). Each basic window thin (0.030 in.) chemically tempered bonds within the community. When material--glass, acrylic, and glass ply. This glass does not shatter on team members feel pride for a polycarbonate--have their particular impact and only retains damage at the community system, they tend to take a advantage. Where vandalism is severe, impact site. The interlayer adhesive personal interest and responsibility for sacrificial plies and peel plies provide system prevents the glass from spalling. the system. the best protection. Glass spall can be This type of system would both prevent eliminated or reduced by using an crazing and abrasion damage of acrylic RECOMMENDATIONS FOR interior anti-spall film. Increased bus windows and substantially increase FUTURE PROCUREMENTS durability of acrylic and polycarbonate durability of exterior surfaces. Cost may be achieved with different coating would be a significant factor, however. Recommendations for future systems like the durable, soft, abrasion Another emerging technology is procurements include procuring flat and chemically resistant polyurethanes diamond-like-carbon (DLC) coatings, windows and specifying window used in the aircraft industry, or with which have very attractive properties systems that allow very fast change-out thin glass exterior ply technologies for this application, including excellent (5 min or less is desirable). To achieve currently under evaluation. quick 5

There are several recommendations for vehicle brush washing damage and · Testing of polycarbonate future work. They are extend service life; plies to provide sacrificial ply · Evaluation of thin glass ply vandalism resistance and spall · In-depth evaluation of technologies on the exterior of plastic protection for glass; and candidate coatings (such as windows to resist vehicle brush · Study of transit polyurethanes or DLC) on washing damage and extend service police/security prevention techniques polycarbonate and acrylic to resist life; and prevention technology.