FRA GradeDec Software

The FRA developed the GradeDec.NET (GradeDec) highway-rail grade crossing investment analysis tool to provide grade crossing investment decision support. The GradeDec provides a full set of standard benefit ‑cost metrics for a rail corridor, a region, or an individual grade crossing. Model output allows a comparative analysis of grade crossing alternatives designed to mitigate highway-rail grade crossing collision risk and other components of user costs, including highway delay and queuing, air quality, and vehicle operating costs. The online application can be accessed via FRA’s website.(47) The GradeDec is intended to assist State and local transportation planners in identifying the most efficient grade crossing investment strategies. The GradeDec modeling process can encourage public support for grade crossing strategies, including closure and separation, where project success often depends on getting the community involved in the early planning stages. The GradeDec computes model output using a range of values for many of the model inputs. This process allows individual stakeholders to influence how different investment options are weighed and evaluated. The GradeDec implements the corridor approach to reducing collision risk that was developed as part of the Transportation Equity Act for the 21 st Century’s Next-Generation High-Speed Rail Program (TEA-21, 1998, PL, 105-178). This approach can be an effective means of reducing the overall capital costs involved in constructing facilities for high-speed passenger rail service (at speeds between 111 and 125 mph), where grade crossing hazards and mitigation measures can be a major cost factor. The corridor approach can be used to demonstrate that acceptable levels of collision risk have been reached for all rail corridors, train types, and speeds. For example, exceptions to the proposed federal rule mandating whistle-sounding at all highway-rail grade crossings can be made by showing that appropriate safety measures have been taken to mitigate the additional risk otherwise presented by trains not sounding their horns. The GradeDec uses simulation methods to analyze project risk and generate probability ranges for each model output, including B/C ratios and net present value. The software also analyzes the sensitivity of project risk to GradeDec 2000 model inputs to inform users which factors have the greatest impact on project risk. (48) MUTCD Interpretations, Experimentation, Changes, and Interim Approvals As technology and research continue to progress, updates to guidance and standards outlined in this Handbook, as well as the MUTCD, may be required. The FHWA periodically updates the MUTCD; however, updates to the document must go through a federal “rulemaking” process which requires posting the document in a Notice of Proposed Action (NPA) and addressing comments received before posting the revised document as a “Final Rule.” A number of years may be required to provide a full update to the MUTCD. The 2009 MUTCD with revisions 1 and 2 is available at https://mutcd.fhwa.dot.gov/ pdfs/2009r1r2/pdf_index.htm . 137It should be noted that a “hotlinks” PDF version of the MUTCD which contains the most current updates to the MUTCD providing links to official interpretations, corrections to known errors, and other external documents is available at https://mutcd.fhwa.dot.gov/pdfs/2009r1r2/ hotlinksfeatures.htm . During the intervening period between MUTCD updates, FHWA may provide “Interpretations” or “Interim Approvals” and practitioners may petition FHWA to conduct “Experimentation” for a new treatment following procedures presented in Section 1A.10 of the MUTCD:

•Interpretations—Practitioners can request FHWA to clarify the intent of MUTCD provisions by formally requesting an official “Interpretation.”

•Interim Approvals—Section 1A.10 of the MUTCD contains a provision authorizing the FHWA to issue Interim Approvals. Such approvals allow the interim use (pending official rulemaking) of a new traffic control device, a revision to the application or manner of use of an existing traffic control device, or a provision not specifically described in the MUTCD. Interim Approvals are considered by the FHWA Office of Transportation Operations based on the results of successful experimentation, studies, or research, and an intention to place the new or revised device into a future rulemaking process for MUTCD revisions.

•Experimentation—Experimentation provides a means for a practitioner to install and evaluate a new device. Although experimentation is a time-consuming process which requires installation of testing and potentially removal of a trial device, it does provide an opportunity to establish new treatments. Practitioners should be aware of the following:

•Design, application, and placement of traffic control devices other than those adopted in this Handbook should be prohibited unless the provisions provided in Section 1A.10 are followed.

•Except as provided in Paragraph 4, of Section 1A.10, requests for any interpretation, permission to experiment, interim approval, or change should be submitted electronically to FHWA, Office of Transportation Operations, MUTCD team, at the following e ‑mail address: MUTCDofficialrequest@dot.gov.