INTERRA completed a Systemwide contract (2015-2020) with the Illinois Tollway to provide Independent Assurance (IA) work on the entire I-390 and I-88 corridors. INTERRA provided IA services on the Elgin O’Hare Western Access (EOWA) Corridor, Reagan Memorial Tollway (I-88) Corridor and the geotechnical scope on Jane Addams I-90 Corridor. IA engineers were provided to the Tollway’s Materials Engineer, Construction Engineering staff, CM and consultants and performed independent verification of the Tollway’s QC/QA roadway materials program. IA engineer witnessed and verified that QA activities were implemented in accordance with the CQP. IA provided assistance for mix control including HMA and PCC mix designs and PCC trial batches. I-88 involved roadway resurfacing and rehabilitation of existing Interstate roadway with SMA, Warm-Mix Asphalt and specialized mixes, embankment and roadway elevation, ramps, and bridge decks. Scope also included technical specification review and recommendations. This project was completed June 2020. The following services were provided by INTERRA.

  • Reviewed QC and QA material testing data on I-MIRS material data management system
  • Coordinated communication with the Tollway Materials Department, Tollway PMs, and CMs
  • Reviewed data during Test Strip mix placement
  • Provided documentation for daily summary reports and monthly progress meeting reports
  • Monitored subgrade placement, laboratory, asphalt plant production, soils, and aggregates placement inspection and paving operations
  • Monitored subgrade testing for bearing capacity, proof rolling, PGE placement, capping, and backfill compaction
  • Technical specification reviews and recommendations
  • Independent Assurance on Precast Slab Panels for full dept repairs on various locations on I-88 and I-294