LoadPath PDH — PE/NICET supplemental PDH (not FHWA/NBIS refresher training).

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Load RatingOnline self-study

Legal Loads, Specialized Hauling Vehicles and Emergency Vehicles

1 PDH · about 60 minutes · Course no. BR-L02 · Instructor: Michael Craig, PE

About the instructor

Michael Craig, PE is Senior Vice President and Southeast Director at Strinteg Corporation, leading bridge inspection and structural engineering across eight states and Puerto Rico. In 27+ years he has inspected over 4,000 structures and completed 3,000+ load ratings and 160+ load tests. He has managed repair and preservation design for complex bridges, including cable-stayed bridges. He holds PE licenses in twelve states, DC and Puerto Rico, SPRAT Level 1, and FAA Part 107 credentials.

A bridge that rates well for the HL-93 design load can still need posting for the trucks that actually use it. This course covers the three families of legal-load rating vehicles an engineer must consider under the AASHTO Manual for Bridge Evaluation (MBE) and FHWA policy: the routine commercial vehicles (Type 3, Type 3S2 and Type 3-3), the Specialized Hauling Vehicles (SU4 through SU7, screened by the Notional Rating Load), and the FAST Act Emergency Vehicles (EV2 and EV3). For each family it explains where the model came from, what FHWA memoranda require, how the live load factor and multiple presence are handled, and how results are turned into ratings and posting values. Every regulatory statement is drawn from the MBE, the FHWA memoranda of November 15, 2013 (SHVs) and November 3, 2016 (EVs), the FHWA Questions and Answers documents for each, and 23 CFR 650.313.

⬇ Download study guide (PDF)

Learning objectives

  • Identify AASHTO legal vehicles
  • Explain why SHVs were added
  • Describe FAST Act emergency vehicles
  • Decide which vehicles to rate

Outline

  1. Why legal loads are rated separately
  2. The routine commercial vehicles: Types 3, 3S2 and 3-3
  3. Why SHVs were added
  4. The SHV load models and the NRL
  5. SHVs and State law: the decision tree
  6. Comparing vehicles correctly
  7. Posting signs for SHVs
  8. FAST Act Emergency Vehicles: the legal basis
  9. The EV2 and EV3 rating models
  10. Rating rules for EVs: the two exceptions
  11. Posting for EVs: axle and gross limits
  12. Signs, State law, and restriction alternatives
  13. Worked example 1: routine vehicles and SHVs on a 65 ft span
  14. Worked example 2: an EV posting
  15. Worked example 3: a long continuous unit
  16. Common errors and a reviewer checklist
  17. Summary
  18. Open the course (23 screens, 2 knowledge checks)
  19. Final quiz — 10 questions, 70% to pass

References

  1. AASHTO, The Manual for Bridge Evaluation, 3rd Edition, 2018 (with interim revisions)
  2. FHWA Memorandum, Load Rating for Specialized Hauling Vehicles, November 15, 2013
  3. FHWA Memorandum, Load Rating for the FAST Act's Emergency Vehicles, November 3, 2016