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Engineering Methodology

Use each tool within its stated inputs and limits. The site separates standards-derived values, geometric calculations, and user-entered assumptions.

Standards and methods

  • Dry paved-road stopping distance uses the selected ERA Geometric Design Manual (2013), §7.2 and Table 7-2 rows. The level reference and the calculated grade-adjusted distance are separate.
  • The drainage screen uses the ERA Drainage Design Manual (2013), Chapter 5 §5.7 for the Rational method and Chapter 6 §6.12.2 for Manning flow. Full-barrel capacity and uniform ditch depth have separate purposes. Verify inlet and outlet control, headwater, lining and freeboard independently.
  • Flexible pavement traffic classification refers to ERA Flexible Pavement Design Manual (2013), Table 2-8. Cumulative traffic is classified before rounding. Unsupported classes have no layer or overlay preset.
  • Earthwork interval volumes use the average end-area identity and actual distances between sections on one continuous station basis.
  • Review the edition and calculation notes on each individual tool page. References to AASHTO, AACRA and other standards do not make those methods interchangeable or imply that every mode has passed source verification.

How checks are verified

Check source editions, page locators and input units. Compare implemented results with independently calculated examples, boundary cases and invalid inputs. Test file workflows with synthetic examples and inspect the exported rows and formulas. A browser download check does not establish compatibility with every CAD release or satisfy project approval.

The tools process selected engineering files in the browser. The privacy policy describes separate website requests, analytics and contact processing.

Change history

· This version separates dry paved sight-distance references and preliminary hydraulic outputs, corrects upper pavement traffic classes and variable earthwork intervals, and adds four beta review tools for cross-sections, route options, alignment phasing and field test coverage.

Report a discrepancy through the contact page. The editorial and corrections policy explains what evidence to include and how changes are reviewed.