So it's dismal, but the Department for Transport says the estimated £500m needed to bore a tunnel under the plain is a waste of money.
An announcement is imminent on whether it would be cheaper to radically overhaul the project and use new technology to bore a tunnel all the way beneath Tysons, thereby saving the headache of building the elevated train along its busy streets.
In October, the larvae go down the stem and bore a tunnel to the pith, where they transform into chrysalides.
In an attempt to expand the system and add new ratepayers, the county tried to bore a giant tunnel beneath the Cahaba River, Birmingham's main source of drinking water.
The solution, elected officials, labor unions and business groups agree, is to bore a second tunnel through the Hudson Palisades, under the river and into the bedrock of Manhattan.
With their uncontaminated soils and 400-year-old trees supporting thousands of species, ancient woods are irreplaceable, but it's still deemed too expensive to, say, bore an HS2 tunnel under the bluebells of South Cubbington wood in Warwickshire.
A tunnel with a long, single, straight path is comparatively easy to bore with a tunnel boring machine.
As Steve Stofka, a transport blogger, explains, this proposal would require the most expensive type of tunnel imaginable—"It is freaking expensive to bore a ten-mile-long tunnel through an alluvial floodplain under a highly urbanised area and to maintain it, since it will reside below the water table," Mr Stofka writes.
But the more you delve into the details of the plans, the sillier they appear.Take, for example, Amtrak's proposal to bore a 10-mile rail tunnel underneath Philadelphia.
His new company was going to bore an extensive network of tunnels underneath Los Angeles, an "urban loop system" that eventually would be filled with little pods taking people cheaply and quickly around the city.
They employed a used sewer-tunneling machine with a 10-foot-diameter bore to dig a tunnel that formed an 800-foot-diameter ring 60 feet below the surface and constructed the accelerator within the tunnel walls.
