Quietly, quickly and effectively the Hawaii State Department of Transportation (HDOT) has added a full lane of traffic on the west-bound H-1 Freeway from Punahou Street to Pali Highway.
The new lane starts as an extension to the existing auxiliary freeway lane between the Punahou Street on-ramp and the Lunalilo Street off-ramp like so:
The added lane continues onto the viaduct than now has four instead of three lanes! This is a whopping 25% to 30% capacity addition. Numerically it is a 33.3% gain but when a lane addition is effected by narrowing lanes and shoulders, some capacity loss does occur. As you see in these pictures, vehicles fit well on the narrower lanes and after multiple passes, I did not notice any slow downs because of the tighter lanes.
Now the critical Lunalilo Street on-ramp and Vineyard Boulevard off-ramp has five lanes instead of four, like so:
The fourth lane terminates smoothly as the Pali Highway off-ramp.
This lane addition is the result of many months of work at my University of Hawaii Traffic and Transportation Lab, the R. M. Towill Corporation, the Planning, Traffic and Design section of HDOT and others.
Cudos to HDOT for doing it! I look forward to the similar lane addition on the east-bound side.