See my 2010 article on this project:
https://cos-mobile.blogspot.com/2010/09/cap-buffalo-nys-kensington-expressway.html
The current N.Y.S. Kensington Expressway Tunnel project represents the only sensible alternative configuration, of converting the existing trench expressway into a complete corridor tunnel, with a small extension northward (due to the high excavation requirements of removing rock).
And it should at the very least be practical as an initial stage for restoring Humboldt Parkway to Delaware Park, with some revisions: perhaps lower it another 10-18 inches for more substantial tree root area, and most certainly extend the project's excavation northward by at least 350 feet, to facilitate a subsequent project to extend the expressway tunnel & restored Humboldt Parkway to Delavan Avenue, and continue the Humboldt Parkway restoration to Delaware Park/Agassiz Circle atop a likewise buried 198 tunnel.
Nonetheless, it has come under attack of large numbers of comments favoring the absurd idea of filling in the existing Kensington Expressway open trench. That is, to instead place the vehicular traffic upon the surface, necessitating wider roadways and a drastically narrowed green-way median, let alone the significantly steeper ascent grade, for northbound traffic by the Science Museum.
Those that chant "fill it in" claim they seek to restore Humboldt Parkway. But with 70-80K vehicles daily, they conveniently ignore that the project remains connected to expressways at both ends, and that the original Humboldt Parkway lacked connecting expressways. They say they want clean air. Yet somehow repurposing a 65 mph expressway segment as a 30 mph boulevard, with a considerably loader, more polluting northbound climb past the Science Museum owing to a ridiculous edict to destroy urban expressways.
A perusal of the NYSDOT comments received, and of newspaper articles indicates many have so accepted dogma over rationality in favoring a step backwards by filling in the trench for creating an 8 to 10 lane (or perhaps a 6 lane) surface arterial with a considerably narrower attempted recreation of Humboldt Parkway.
Comparably little attention has been given to the planning feasibility.
Obviously, we don't [yet] have a project extending the tunnel under a linear park to Agassiz Circle because of the costs- am guessing perhaps $4 1/2 billion rather than $0.9 billion, owing to the sheer amount of required excavation. Alas the 198 connection only has a brief trench passing under only two street crossings, with the rest surface level.
But what about the feasibility of the current project being followed by a second project to extend the Kensington Expressway Tunnel & Humboldt Parkway further north?
For the expressway tunnel to continue north, it must cross a buried 24 ft wide, 14 ft deep concrete waterway conduit for Scajaquado Creek, extending about 19 feet underground. If this conduit is unaltered, the expressway tunnel would therefore descend from about 25ish to 40 below ground level to pass beneath, increasing excavation amounts.
This 25 to 40 descent would be eliminated if the conduit were replaced and replaced with a new conduit that drops down to pass beneath the underground expressway, and feeds into perhaps an 1/4 to 1/3 mile of new receiving downstream connector to maintain a gravity flow waterway.
This 25 to 40 descent would alternately be significantly reduced if the conduit replacement instead remained over the expressway tunnel, with replacing the 24ft x 14ft conduit perhaps with a pair of 48ft x 4ft conduits, or perhaps an array of pipes- shaving about 10 feet from the conduit's depth, therefore allowing the expressway at 30 - 32 feet below ground level, without any lengthy replacement downstream connector.
If the expressway tunnel were only as low as 30 feet underground, that would be more than sufficient than the 27 or 28 feet that activists seek for establishing a more ample space for the roots of the trees
But where is any official or otherwise plan for this required underground waterway/expressway crossing? The official draft design report (see pp 24-25) can only say:
The buried Scajaquado Creek is beneath the overhead pedestrian bridge.
Extending the tunnel in a separate project requires re-excavating the transition. Hence to better facilitate this, the current project must be revised to extend the expressway tunnel excavation about another 650 feet to meet the conduit. This gets the "hard" more time consuming excavation done, so the successive project could instead simply remove comparably soft fill material used for the interim tunnel to surface transition. This also provides a potential staging area for the successive project to more cost effectively extend the tunnel by small tunnel boring machines (TBM) used in underground utilities, perhaps 5 or 6 feet as the initial stage of excavating the extension towards Delavan Avenue.
This project is to be an initial stage project.
For it to be so, it must facilitate rather than hinder the multi stage process.
Yet as it now is, it falls markedly short with its limiting its excavation to simply the new tunnel to surface transition between Sidney Avenue and Hamlin Road. This means that the successive future project to extend this tunnel must perform the entire excavation between Sidney Street and Delavan Avenue excavation, including having to dig out the initial project's tunnel to surface transition, where traffic must be maintained throughout the construction project.
Considerably more suitable is to extend the project to include the anticipatory subsequent tunnel extension's initial 650 feet of hard excavation to meet the buried Scajaquado Creek conduit, and have the interim ascent/descent transition supported by fill that would be considerably easier to remove.
