Data Driven Safety Analysis


Mar 05, 2019


Clemson University

202 Hugo Drive

Seneca, SC



**Participants may find it helpful to bring a laptop or tablet to class, but it is not required

Course Description:

Safety Analysis of Freeway Segments and Interchanges

The 2014 Supplement to AASHTO’s Highway Safety Manual (HSM) introduced new material for the first time since the First Edition was published in 2010. Before 2014, it was impossible to analyze freeways or interchanges using HSM methodologies. But no longer!

This workshop explores how geometric design, traffic control, and other factors affect roadway safety. Participants will learn crash prediction methodologies for freeway segments and interchanges that were published in the HSM, First Edition Supplement (Chapters 18 and 19).

Attendees will also gain experience using two free tools that automate the application of HSM methodologies:

  • Enhanced Interchange Safety Analysis Tool (ISATe)
  • Interactive Highway Safety Design Model (IHSDM)

These two tools help users predict the safety effects of varying freeway segment and interchange designs.

Workshop Learning Outcomes

  • Describe how freeway and interchange safety analysis can support decision-making for project design choices.
  • Optimize investments by applying the most current analytical methods to quantify safety.
  • List examples of how the HSM chapters on freeway segments and interchanges could be applied during project decision-making.
  • Use ISATe and IHSDM to apply the HSM predictive methodology to assess safety on freeway segments and interchanges.

Learn the ISATe and IHSDM Safety Analysis Tools

The workshop will focus on learning to use the HSM’s two free companion tools to analyze design alternatives and interpret results for freeway segments and interchanges. These tools automate the process of applying crash prediction models from the HSM in Chapters 18 and 19.

The ISATe is a free, macro-enabled Excel workbook primarily used for small freeway segments. Users manually enter data for each individual segment, interchange, and cross street. CMF values and intermediate calculations are visible within the Excel interface so users can follow the calculations.

The IHSDM (www.ihsdm.org) is a free, standalone software suite that implements all HSM Part C predictive methods. It can be applied to both freeway and non-freeway network components (e.g., cross-roads, connectors, local roads, and intersections) and is appropriate for both complex and simple analysis projects.

Additional features include:

  • Two options for data input and analysis:
    • Station-Based: automatically segments the highway into homogeneous segments as per HSM Part C.
    • Site-Based: functions similar to a spreadsheet tool and is especially useful for projects where detailed, station-based geometry is not available.
  • The ability to import LandXML files (i.e., project alignment data) from highway design software.
  • A Highway Viewer providing graphical representations (e.g., plan view) of the design.
  • A Calibration Utility to help agencies implement HSM calibration procedures.
  • Extensive documentation, including a tutorial with step-by-step exercises.

Workshop participants will apply each tool to a real-world alternatives analysis case study. The exercise will compare analysis results for two alternative designs.

Class registration is from 8:00-8:30. The class will begin at 8:30. Lunch will be provided. We should adjourn around 4:30pm.

Course Fee:
The registration fee for the workshop is $120.00 per person. All South Carolina city, county, or state employees receive a LTAP scholarship registration fee of $55.00. The fee includes course materials, break refreshments, and the noon luncheon.

This course has a maximum of 30 students, and will be capped at this number. Advanced registration is encouraged so that an accurate estimate of the number of workshop participants can be obtained. Workshops with low advanced registration will be subject to cancellation.

Payment Policy:
Payment must be received no later than 5 business days prior to the workshop. If your registration payment is not received by then, you will not be guaranteed your slot in the class.

Cancellation Policy:
If you cancel your registration more than 72 hours before a class, your registration fee will be refunded, less a $35 processing fee. If you do not cancel before the 72 hour deadline your registration fee will not be refunded. You may send a substitute in your place, provided that you inform us of the substitute’s name no later than 24 hours before the training. No-shows will not have their registration fee refunded.

If you have any questions regarding workshop registration please contact Brittany Wirtz at 864-656-4383 or bwirtz@clemson.edu.