Minnesota Department of Transportation

511 Travel Info

Technical Certification Program

Print or download the listed course materials, and bring them to class.

Grading and Base Tester Certification (GBTC)

Prerequisites for certification

  • You must be certified in Aggregate Production Tester (APTC) before this certification will be awarded to you.
  • We highly recommend you take the courses in this order: APTC, GBTC.

Expiration and recertification options

  • This certification expires after five seasons.
  • A recertification must be completed before the end of the fifth training season.
  • If your certification has recently expired and you have relevant work experience, you may apply to regain MnDOT certification through a Recently Expired Certification Exam. Otherwise, you must take the initial certification course again to regain certification.

Class logistics

  • Learning mode: In person for classroom and lab
  • If you need to register: Learn about the certification process and then register for the class.
  • Logistics: See the Registration Confirmation and Class Reminder emails from Lake Superior College for class dates, time, location, and directions. Time will be provided for on- or off-site lunch. No meals or beverages will be provided.
  • Learning differences and accommodations: If you have a disability or learning issue, either permanent or temporary, which might affect your ability to perform in a class, the online exam, or the performance exam, contact Suzanne Johnsrud, 218-428-1002, to discuss possible accommodations.
  • Summary: GBT Certification Summary (PDF)
  • Professional development hours (PDHs): 18
  • Lake Superior College course credits possible: 1 (you must complete an LSC course credit form)

What to bring to class

Print and bring to class 

Download these files on a laptop or tablet you’re bringing to class; OR print and bring to class

Reference books/manuals to bring (hard copy or electronic)  

  • None

Also bring to class

  • Calculator
  • Paper and pencil/pen
  • Laptop/tablet (recommended)
  • Face mask (for health and safety, if needed)
  • Lunch and beverages to eat/drink if you plan on site  
  • Hard toed shoes and other safety gear for lab (recommended)

About the certification exams

Written exam process

  • You will have 120 minutes to complete the 50-question written exam online.
  • You must score 70% or higher to pass; if you score 60-69%, you may request a retest.
  • The exam will open for you at the end of the last day of class.
  • You must complete the exam within one week after it is open for you, meaning the same day the following week.
  • Find your exam to take it once it is open for you.

Written exam topics (approximate percentage of exam)

  • Content knowledge needed for the work (15%)
  • Procedures and documentation (40%)
  • Specific test procedures (45%)

Materials allowed during the written exam

This is an open book exam. You may use the training manual and all other course materials during the exam. A calculator is provided within the online exam.

Performance exam

  • You will complete a performance exam during your lab session on the second day of class.
  • The certification will not be awarded until the performance exam is complete and recorded.