@BOOK{NAP14273, author = "Transportation Research Board and National Academies of Sciences, Engineering, and Medicine", title = "Guidelines for Guardrail Implementation", doi = "10.17226/14273", abstract = "TRB\u2019s National Cooperative Highway Research Program (NCHRP) Report 638: Guidelines for Guardrail Implementation explores guidance on selecting the appropriate barrier performance level for the installation of longitudinal barriers.The following appendices to NCHRP Report 638 are only available online.\u2022 Appendix A, Guardrail Use Guidelines for Benefit\/Cost = 2\u2022 Appendix B, Guardrail Use Guidelines for Benefit\/Cost = 3\u2022 Appendix C, Guardrail Use Guidelines for Benefit\/Cost = 4\u2022 Appendix D, Guardrail Use Guidelines for Benefit\/Cost = 1", url = "https://nap.nationalacademies.org/catalog/14273/guidelines-for-guardrail-implementation", year = 2009, publisher = "The National Academies Press", address = "Washington, DC" }