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66 C H A P T E R 5 An integral part of the assessment process is to communicate the results via coding and mark- ing. Coding is the process of using a shortened notation or series of letters, numbers, or symbols to indicate the integrity of a structure, its components and elements, and other parameters asso- ciated with it. Marking is the process of applying an identifiable code to the structure in order to inform others of its condition. This can be done physically or digitally. The physical marking of a structure is sometimes referred to as âposting.â 5.1 Volume 3 Overview In addition to the Assessment Process Manual described in Chapter 4, a separate field manual was developed and is available as Volume 3: Coding and Marking Guidelines. Volume 3 was devel- oped as a flipbook resource for the PDARs to use directly in the field in order to enable rapid yet effective evaluation of highway structures after emergency events. Volume 3 is divided into three parts so as to enable efficient access to information. Part I of Volume 3 provides concise background information that is helpful for performing evaluations of highway structures during emergency situations. The chapters included in the background are the introduction, overview of highway structure safety evaluation, proposed preliminary damage assessment guidelines, and an overview of emergency events. These chap- ters should be reviewed prior to conducting evaluations of highway structures. Part II discusses the specific PDA procedures and considerations for bridges, tunnels, culverts, walls, and overhead signs. Each chapter provides a general overview of the highway structure; a schematic; the PDA procedure; a list of elements; and the damage states that define minor, mod- erate, and severe damage levels for each element. For each highway structure type, assessment forms are included to be used as reference for collecting damage data during the emergency events. In practice, these forms should be completed digitally with a smart app (See Chapter 6 of this volume) or manually with paper copies [Microsoft Word files of the forms are available on the TRB website (www.trb.org)]. Part III contains example damage photos that can be used to help rate the damage level for each element of the structure. Pictures are included for bridges, tunnels, culverts, walls, and overhead signs, as well as scour. Classification examples are provided for minor, moderate, and severe damage, when applicable. Individual DOTs may wish to adapt these as relevant to their infrastructure and hazards. In some cases, there may not be photos for all three damage states. For these instances, some judgment will be required of the PDAR when selecting a damage rating. Volume 3 also contains several appendices including equipment lists, field safety consider- ations, contact list templates, an emergency route template, and an assessment form example. It Coding and Marking Guidelines
Coding and Marking Guidelines 67 is envisioned that each SHA will augment these pages with information specific to their agency so that it is readily available for each PDAR. 5.2 Coding and Marking Process A coding and marking system was developed to support uniform communication between inspectors, maintenance crews, engineers, and others as necessary. The terms INSPECTED, LIMITED USE, and UNSAFE were chosen to be consistent with the process used for buildings (i.e., ATC-20). The term INSPECTED was selected because many bridges in use today are clas- sified as âstructurally deficient.â Given that PDAs should take no more than 30 minutes per structure, the assessment is likely not detailed enough to imply any structural capacity other than that the structure appears to be in the same condition as it was prior to the emergency event. To maintain consistency within the whole process, the terms were also used for DDA and EI. Given the scope and range of damages that can occur from the wide variety of emergency events that are possible across the country, a simplified taxonomy was developed in order to group common forms of damages so that a systematic process could be implemented that is nearly independent of the hazard type as summarized in Section 3.1 of this volume. All inspected structures within the impacted region should be marked both physically (in the PDA stage) and digitally (in the FR and PDA stages) after an assessment is conducted and the coding for the structures is established. Structures should be marked physically in an obvious location on both ends of major elements of the structure using placards affixed with a color decal of the coding option (see Figure 5-1 for the placard and Figure 5-2 for the coding options). For example, the placard with decal would be on the right-hand side of the approach to the bridge (i.e., on railings or fixed structural elements at both bridge abutments). These posting placards and decals should be available at all offices and in the inspection vehicles. Figure 5-1. Example marking placard.
68 Assessing, Coding, and Marking of Highway Structures in Emergency Situations: Research Overview Structures should be marked digitally in a central database and/or GIS map that is accessible to authorized staff with a secure connection. The use of QR codes on the placard in concert with smart devices (i.e., smartphones or tablets) or stand-alone readers can significantly reduce coding time and improve information flow and reliability between personnel and across agencies. PDARs should have decals with QR codes or have access to a mobile QR code printing machine. Guidelines on how these should be implemented are discussed in Chapter 6 of this volume. The marking (and hence contents of the QR codes) must clearly indicate the agency that made the marking, the assessment stage (i.e., PDA or DDA), the date and time of the assessment, the resultant coding (i.e., INSPECTED, LIMITED USE, UNSAFE), actions taken (e.g., close struc- ture, close lane), and initials of the PDAR. After undergoing PDA, highway structures should be marked with one of two placards: INSPECTED or UNSAFE (refer to Figure 4-1). If a structure is marked UNSAFE during a PDA evaluation, it will be further evaluated using DDA. During DDA, highway structures are marked with one of three decals on a new/updated placard: INSPECTED, LIMITED USE, or UNSAFE (refer to Figure 4-1). This posting lets the SHA, respondents, inspectors, and the public know the condition of the structure as well as the date and time the assessment was performed. The system used for marking a highway structure and the definition of each marking category are summarized in Table 5-1. In addition to marking a highway structure, it may be necessary to designate restricted use of cer- tain parts of the structure that may be hazardous areas. For example, if a bridge deck is badly cracked or raised on one side, traffic should be redirected onto the non-damaged portion of the bridge. Figure 5-2. Coding options for PDA (left) and DDA (right). These can be printed as decals to be placed on the placard shown in Figure 5-1.
Coding and Marking Guidelines 69 Table 5-1. Highway structure coding and marking classifications for PDA and DDA. Marking Classification Description INSPECTED (Green) This classification utilizes a green color code and indicates that, subject to the inspection at the current stage, no apparent damage was found and the pre-event load-carrying capabilities of the structure appear to be fully intact. No restrictions on use. LIMITED USE (Yellow) This classification utilizes a yellow color code and indicates that dangerous conditions are believed to be present. Usage is restricted to ensure public safety. The restrictions to use must be clearly defined by symbols and can include lane closures, vehicle load limits, or use by emergency vehicles only. UNSAFE (Red) This classification utilizes a red color code and indicates that extreme hazards are present, the structure is in imminent danger of collapse, or the structure has collapsed. The structure is closed to all traffic.
