From a rather hot-headed post I made on Yahoo, when I found out the projection was for a gradual increase to 27,500 vehicles per day:
Roadway capacity: 2,250 cars per hour per lane at 55 MPH, which would be roughly 2,200 vehicles per hour per lane (assuming a fairly low truck mix). Times 3 lanes = 6,600 vehicles per hour in each direction, 13,200 vehicles per hour total.
6 AM to 9 AM: Total traffic, both directions, 5,618. Average per hour: 1,873. That's about 14% of capacity.
9 AM to 1 PM: Average per hour: roughly 2,000. That's about 15% of capacity.
4 PM to 7 PM: Total traffic, eastbound, 5,389. Average per hour: 1,796. That's about 27% of capacity.
5 PM to 6 PM: Total traffic, eastbound, 1,907. That's about 29% of capacity.
The road was running at 14-15% all morning long. In the peak direction during the PM peak period, it made it up to about double that. A healthy freeway ought to be running at least 40% of capacity during the day, or roughly 2,500 vehicles per hour in three lanes. (In the urbanized Northeast, I'd expect more like 3,000+.) Peak period may be closer to 75%-80% of capacity, or roughly 4,500 to 5,000 vehicles per hour in three lanes. For reference, this correlates well with other roadways whose data I've run through before.
The ICC ended up with a first day count of 39,000 vehicles total in both directions. A lot of people took it because it's the first day, but a lot didn't take it early in the day, so let's say that balances out. Let's be generous and say 40,000 vehicles total in both directions. It's an urban area, so figure peak hour is no more than 9% of that, or 3,600 vehicles per hour. (Note that this works out pretty well with the 5-6 PM figure.) That's 600 vehicles per lane per hour, which is still Level of Service A!!! You should never have LOS A or even B on an urban highway during rush hour. A well designed freeway should hit LOS C, which is roughly 1,500 vehicles per lane per hour. That's easily accommodated by the roadway design and allows plenty of room for growth. Back that out to 9,000 vehicles per hour and divide by 9%. You get 100,000 vehicles per day.
When will the ICC hit 100,000 vehicles per day? When will it even hit HALF that? This should have been a four-lane parkway at best. In fact, even a FOUR LANE AT GRADE BOULEVARD would function adequately, and a six-laner would have no problems whatsoever. This supports the "waste of money" argument. Don't see how costs will ever be recouped.