I-25 & CO 402 Construction Zone - Stolfus and Associates
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I-25 & CO 402 Construction Zone

About This Project



  • Major construction on I-25 in both directions in northern Colorado
  • Traffic is operating with two lanes in each direction, minimum shoulders, and concrete barrier on both sides



  • What: Multi-vehicle crash PDO (Property Damage Only)
  • When: Saturday, November 10, 2018, 10:50am
  • Where: South-bound I-25 within construction zone
  • Problems:
    • Closest responder is one exit away
    • Queue behind crash delays response and size-up by at least 10 minutes
    • Congestion persists for 3 hours
  • Negative Impacts:
    • Estimated road user delay cost was over $30K
    • Over 1300-person hours wasted



  • Stolfus & Associates conducted collaborative traffic study
  • Engaged multiple stakeholders including:
    • Emergency first-responders
    • Municipal leaders



  • What: Multi-vehicle with tow required
  • When: Wednesday, January 2, 2019, 3:50pm
  • Where: North-bound I-25 within construction zone
  • Positive Impacts:
    • 11 minutes to clear scene from traffic
    • Use of mutual aid channel
    • Responder access to crash scene via pavement not open to the public within active construction area
    • Total traffic disruption approx. 1 hour