Appendix I

Traffic and Revenue Model Assumptions

Growth Rates

•  Background 1.3%

•  Congestion Driven (2% additional)

•  Toll Inflation Factor (1% additional)

Capacity Constraints

•  Elgin-O'Hare Extension/O'Hare Bypass

  For 120,000 vehicles per day (VPD) to 150,000 VPD, reduce congestion driven growth by 1%

  Over 150,000 VPD, reduce growth to background growth only

  Cap volume at 170,000 VPD

•  Roadways feeding Elgin-O'Hare Extension/O'Hare Bypass

  No constraints on I-294 - traffic diverted from I-290 will be able to use I-294 for access

  No constraints on I-90 to the north where bypass connects

  All ramps to and from the proposed roadway will have sufficient capacity

Western Terminal Access

•  All traffic pays toll to enter the western terminal 

Tollelasticity

•  33% reduction in traffic for doubling of toll 

Ramp up

•  5 years for road construction

•  3 years for western terminal

Electronic Toll Share (I-PASS)

•  60% opening day

•  Escalate to 80% in 2030

Toll Rates

•  3% annual growth rate based on CPI rounded to the nearest nickel

•  Tolls increase every 3 years