Excellent
Cycle.travel shows the alternative, preferred route as 16.4 km & 390mtr climbing.
The direct (over the top) route if you have the bike, the legs, the weather and the brakes is about 5.5km & 330mtrs.
The direct, direct route (ignoring topology - so what the tunnel must deliver) is 60mtrs in the 3.142km.
A hell of an improvement for the locals that could make use for it and no doubt an enormous tourist magnet.
Queensbury tunnel next please.