Detailed guidelines are provided for the development of specifications for the procurement of durable and vandal-resistant bus and rail vehicle passenger-side windows and window systems. The guidelines provide information on the different types of window systems and materials; their strengths, weaknesses, special features, and costs; and other information. Several relatively new materials are discussed including sacrificial plies, peel-ply protective films, anti-spall films for glass, and aerospace coating and transparency technologies. The guidelines also include specific tests and acceptance criteria that can be used to assess durability, as well as recommend practices for ensuring that the procured window glazing system is easily replaced, and that repair and refurbishment are considered up-front during the initial specification-development process. Finally, the guidelines include short, lessons-learned discussions for each type of specification requirement.
Transit agencies expend considerable resources procuring and maintaining bus and rail vehicle passenger-side windows. Plastic and glass are the two predominant materials used for these windows. Increasingly, both materials have become subject to costly damage caused by vandal etching. In addition, glazings are subject to potential damage from cleaning chemicals, mechanical wash brushes, and harmful environmental conditions such as ultraviolet sunlight. Compounding these problems, most current window designs make it difficult to replace damaged glazing in an efficient and cost-effective manner. As a result, there is a need in the transit industry for more reliable passenger-side window glazing.
Research was undertaken by the University of Dayton Research Institute to (1) compile information on current and emerging window glazing technologies with potential applicability to the transit industry and (2) develop guidelines to assist transit agencies in the preparation of procurement specifications for transit vehicle passenger-side window glazing. Extensive surveys of domestic and foreign transit systems were conducted to obtain information on transit window-related issues, including vandalism and durability. In addition, the researchers surveyed window-system and material manufacturers and suppliers serving transit and other industries; transit bus and rail vehicle manufacturers; and relevant research organizations to obtain information on existing and emerging technologies that result in longer lasting, more durable transit glazing systems. Based on the information collected, procurement specification guidelines were prepared.
The procurement specification guidelines have been published as TCRP Report 15,
"Procurement Specification Guidelines for Mass Transit Vehicle Window Glazing." An unpublished companion report prepared under this project and entitled Enhancement of Vehicle Window Glazing for Vandal Resistance and Durability-Final Report
, provides the details of the various surveys completed during the research effort. The report also contains a historical overview of graffiti and vandalism and discusses prevention approaches to the problem. Special attention is focused on the need for a cooperative integrated team approach, which includes operators, security, and maintenance personnel, with a zero-tolerance approach to controlling vandalism. An executive summary of this report has been published as TCRP Research Results Digest 9,
"Responding to Vandalism of Transit Bus and Rail Vehicle Passenger Windows."
TCRP RRD 9
and TCRP Report 15
are also available in portable document format (PDF). Double-click on the files below to access the documents. (A free coy of Adobe Acrobat Reader is available at www.adobe.com). The final report for the project is available on request.
TCRP Research Results Digest No. 9
TCRP Report No. 15