6K pdvph is higher than the threshold for building controlled-access highways.  

The eastern Gardiner has quite variable traffic and averages don't capture it well, which why other stats like the 100th hour are used, and which are also too high for the urban boulevard alternative. If it is replaced with a wider urban boulevard, the throughput drops and travel time grows. 

The original cost for reconstruction of the eastern Gardiner offers positive NPV.  The final actual cost though is likely to be far from it. That's where your argument would be stronger.  There is plenty of volume to justify a controlled access route.  There's just not enough time and fuel savings to warrant more than $1.3B.