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From page 77... ... NATIONALLY COORDINATED EVALUATION RESEARCH 77 Annex 3-1 Summary of Procedural Guides to In-Service Evaluation of Roadside Safety Devices The sections below describe four past or current activities to develop and demonstrate data collection and analysis methods for in-service evaluation of roadside safety devices: • The pilot in-service evaluation of guardrail end treatments conducted by FHWA (FHWA n.d.) , • The AASHTO-FHWA Task Force guardrail end treatment investigations (Joint AASHTO-FHWA Task Force on Guardrail Terminal Crash Analysis 2015) Read the entire page →
From page 78... ... 78 PERFORMANCE EVALUATION OF GUARDRAIL END TREATMENTS TABLE 3-2 Data Elements Used in Three Procedures for In-Service Evaluation of Roadside Devices Data Elements Relevant to Evaluation of Roadside Safety Device Evaluation Procedure Washington State DOT Demonstration of NCHRP Report 490 Procedure (Igharo et al. Read the entire page →
From page 79... ... NATIONALLY COORDINATED EVALUATION RESEARCH 79 TABLE 3-2 Data Elements Used in Three Procedures for In-Service Evaluation of Roadside Devices Data Elements Relevant to Evaluation of Roadside Safety Device Evaluation Procedure Washington State DOT Demonstration of NCHRP Report 490 Procedure (Igharo et al. Read the entire page →
From page 80... ... 80 PERFORMANCE EVALUATION OF GUARDRAIL END TREATMENTS TABLE 3-3 Comparison of Proposed Nationally Coordinated Evaluation Research Program with Selected Past In-Service Evaluation Procedures Nationally Coordinated Evaluation Research Program Evaluation Procedure Washington DOT Demonstration of NCHRP Report 490 Procedure (Igharo et al. Read the entire page →
From page 81... ... NATIONALLY COORDINATED EVALUATION RESEARCH 81 TABLE 3-3 Comparison of Proposed Nationally Coordinated Evaluation Research Program with Selected Past In-Service Evaluation Procedures Nationally Coordinated Evaluation Research Program Evaluation Procedure Washington DOT Demonstration of NCHRP Report 490 Procedure (Igharo et al. Read the entire page →
From page 82... ... 82 PERFORMANCE EVALUATION OF GUARDRAIL END TREATMENTS • Property-damage-only and minor injury crashes are to be identified and documented by the state agencies. Fatal and serious injury crashes are identified by the states and investigated by NHTSA Special Crash Investigation (SCI) Read the entire page →
From page 83... ... NATIONALLY COORDINATED EVALUATION RESEARCH 83 minor injury crash investigations were developed by FHWA working with the states and NHTSA. • Data collection includes a standard set of photographs to be taken at each crash site. Read the entire page →
From page 84... ... 84 PERFORMANCE EVALUATION OF GUARDRAIL END TREATMENTS published soliciting cases (Federal Register 2014) Read the entire page →
From page 85... ... NATIONALLY COORDINATED EVALUATION RESEARCH 85 FIGURE 3-1 In-service performance evaluation process proposed in NCHRP Report 490. Read the entire page →
From page 86... ... 86 PERFORMANCE EVALUATION OF GUARDRAIL END TREATMENTS In the data collection phase, the manual includes instructions for four processes: prompt notification to the evaluators that a crash within the scope of the evaluation has occurred, assembly of data on each crash from preexisting sources (police reports and maintenance reports) , collection of data at the site of the crash, and monitoring the frequency of unreported crashes. Read the entire page →
From page 87... ... NATIONALLY COORDINATED EVALUATION RESEARCH 87 and manpower resources while achieving the basic objectives [of evaluation] " (van Schalkwyk et al. Read the entire page →
From page 88... ... 88 PERFORMANCE EVALUATION OF GUARDRAIL END TREATMENTS FIGURE 3-2 Data form for recording end treatment postcrash condition. SOURCE: Igharo et al. Read the entire page →
From page 89... ... NATIONALLY COORDINATED EVALUATION RESEARCH 89 FIGURE 3-2 Continued. Read the entire page →
From page 90... ... 90 PERFORMANCE EVALUATION OF GUARDRAIL END TREATMENTS Presumably a threshold minimum crash severity or device damage severity would be specified for triggering creation of a file. The project developed forms for the site investigations -- a shorter version for the Phase I evaluation and a more detailed form for Phase II evaluations. Read the entire page →
From page 91... ... NATIONALLY COORDINATED EVALUATION RESEARCH 91 Both forms are much less detailed than the forms developed in NCHRP 490. The TTI report cites the NCHRP 490 procedure and states that a simpler data collection process was necessary in Texas to be compatible with the time and budget constraints in the agency's maintenance department (van Schalkwyk et al. Read the entire page →
From page 92... ... 92 PERFORMANCE EVALUATION OF GUARDRAIL END TREATMENTS example, if the failure rate of a device is 5 percent, the probability that two or more failures will be observed in 50 crashes is more than 70 percent, and such an observation ought to be sufficient to trigger follow-up. In the pilot of the TTI procedure, eight of 28 collisions with impact attenuators were coded as "did not perform as intended." The researchers judged this observation as sufficient evidence to warrant further investigation (van Schalkwyk et al. Read the entire page →
From page 93... ... NATIONALLY COORDINATED EVALUATION RESEARCH 93 Johnson, N Read the entire page →

From page 77...

... NATIONALLY COORDINATED EVALUATION RESEARCH 77 Annex 3-1 Summary of Procedural Guides to In-Service Evaluation of Roadside Safety Devices The sections below describe four past or current activities to develop and demonstrate data collection and analysis methods for in-service evaluation of roadside safety devices: • The pilot in-service evaluation of guardrail end treatments conducted by FHWA (FHWA n.d.) , • The AASHTO-FHWA Task Force guardrail end treatment investigations (Joint AASHTO-FHWA Task Force on Guardrail Terminal Crash Analysis 2015)