Toll tunnel under Long Island Sound NY proposed - Sound Link

November 26, 2007

A toll tunnel is being proposed under Long Island Sound to provide a new link between Long Island and mainland New York state in Rye. Called the Long Island Cross Sound Link (LICSL) the twin 3 lane tunnel would run between the Seaford-Oyster Bay Expressway (NY135) in Syosset near the Long Island Expressway (I-495) and I-95 and the Cross Westchester Expressway (I-287) in Rye. It would be the first crossing of the Sound between Westchester and Nassau counties, and about 14km (9 miles) further east out of the Sound than the present furthest east crossing - the Bronx Whitestone Bridge operated by MTA Bridges and Tunnels.

The Sound is a minimum 10km (6 miles) wide at the proposed tunnel crossing point but good portal points from which the tunnel might emerge make it necessary to make the total length of the tunnel some 26km (16 miles) to 28km (17.5 miles) long.

Proposers are Long Island based entrepreneurs Vincent Polimeni and his son Michael, engineers Hatch Mott MacDonald, bankers Bear Stearns, and Rubenstein Assoc PR people.

Michael Polimeni told us in an interview today the team has been quietly "shopping" the project to officials and opinionmakers before going public with it last week.

He says the reception is "good, better than I expected."

He says: "Everyone is intrigued. It's got legs, this thing. Very few people totally dismiss it. Most people want to know more. They want more detail."

The group hopes to get sufficient political push behind the project to have it adopted by the state DOT for alternatives analysis, environmental impact study, and other project development work.

Financially solid

A Bear participant says that his preliminary analysis shows it is financially solid.

"This really has all the look of being a solid project," he told us.

People who work on toll projects there reviewed earlier proposals for a crossing - a bridge - and the formal traffic and revenue studies done by Vollmer Assoc. Then they got traffic counts on the major present routes, looked at forecast increases and applied some conventional diversion factors to get estimates of traffic. That is in the range 60k to 80k/day in 2025.

At an average toll of $25 60k/day gives annual revenue of $548m (that's our figuring - TRnews)

Two big tubes and one smaller

The engineering concept is for two tubes of 16.75m (55ft) diameter to carry 3 travel lanes plus a breakdown shoulder on either side of a central 11.6m (38ft) service, emergency vehicles, and utilities tunnel. There would be connecting cross tunnels at intervals for service and emergencies.

The main tunnels would be built with tunnel boring machines that mine their way forward and place precast concrete wall segments in place as they advance.

Five years would be needed for construction.

Six tunnel lanes could comfortably accommodate 120k vehicles/day.

The large bore tubes with jetfans for ventilation would avoid the low ceiling effect of older 2-lane tunnels.

Toll collection would be all electronic and highway speed. Variable pricing might be used on the approaches to manage traffic and ensure free flow within the tunnel.

Project cost is put by the engineers at somewhere between $8b and $10b.

The crossing would reduce the C-shaped trip from Rye to Syosset from 72km (45mi) to 26km (16mi) on the straight shot tunnel saving 46km (29mi) in distance traveled.

In terms of time 25 to 30mins would be saved in freeflow conditions on both routes.

But if the C-shaped route via the Whitestone or Throgs Neck bridge is at an average speed of 50km/hr (30mph) it takes 90mins and freeflow through the tunnel would save about 75mins. (Our estimates TRnews)

The preliminary estimates of the proposers are that, with the tunnel, traffic on the C-shape route New England Thruway (I-95) between Rye and the Bronx, over the Sound on the Whitestone or Throgs Neck bridges and out east on the Long Island Expressway Queens to Syosset would be reduced 20 to 24%.

Environmental benefits

Vehicle miles traveled, fuel consumed and tailpipe emissions would be substantially reduced. The airhandling equipment in the tunnel could clean the air further.

Polimeni told us his dogleg east on the Long Island landside is designed to minimize subterranean easement by putting most of the tunnel under municipally owned land rather than private land owners. But he said alternatives to the east jog need to be studied. The corridor goes near some of the poshest real estate on Long Island.

History of crossing proposals

According to Steve Anderson ( Seaford-Oyster Bay Expressway (NY135) was originally proposed by Robert Moses in 1954 to connect to a ferry from Oyster Bay LI to Stamford CT. In the late 1960s at the urging of NY Gov Nelson Rockefeller there were a number of bridge studies for crossing the Sound, most further east, and involving connections to the Connecticut shore. A bridge Oyster Bay to Rye was advocated by Rockefeller in 1973.

All these proposals foundered on opposition to land acquisition for the approaches to the crossing. The water part is easy by comparison with getting agreement on the approaches.

Also in the 1960s traffic and revenue calculations that showed the crossings would need substantial tax subsidy support. They would not be self-supporting with tolls, as claimed for this project.

Using the Gmaps Pedometer tool ( with Google maps, we calculate the tunnel as being 28.2km (17.5 miles) long rather than the 26km (16 miles) cited by the proposers.

Just 1.5km (0.95 miles) from the interchange with the Long Island Expressway from Jericho Turnpike (NY25) the southern end of the current proposal goes underground almost eliminating the need to acquire surface rights to land in the Oyster Bay/Woodbury/Laurel Hollow area.

Therefore 6.5km (4 miles) of the tunnel would be under land before arriving at water at one of the Sound's inlets, Cold Spring Harbor.

Nearly 21km (12.9 miles) then would be under water by our calculation. On the northern side there would be another 1km (0.6 miles) to portals just north of the New York State Thruway (I-95) on the Cross Westchester Expressway (I-287).

The engineers think that most of this can occur within the footprint of the existing I-95/287 interchange, though an elaborate collection of new ramps would be needed plus some longish merge diverge lanes on both interstates.

Critics bash with induced traffic argument

Critics are already talking of the induced traffic the project might generate. The mayor of Rye has already decided that rather than rerouting traffic the tunnel would generate a vast increase in traffic, saying it would have "a devastating impact on all of Westchester by clogging the I-287 corridor and I-95 to parking-lot conditions."

At tolls of $25?

However clearly induced traffic calculations are going to be a major source of contention.

Other New Yorkers just don't like cars - not other people's cars anyway - so they are against the roads to accommodate them.

BACKGROUND: Primary beneficiaries of the tunnel would be 3m people living in Nassau and Suffolk counties on Long Island though the nearly 5m people in Brooklyn and Queens would also benefit through reduced traffic on their connections to the Bronx and Westchester.

Long Islanders would be much better connected to Connecticut (3m) and the rest New England (9m). Via the Cross Westchester and the Tappan Zee Bridge they would have another route to northern New Jersey and points west.

Westchester County and Connecticut people would have easier access via the tunnel to jobs, beaches and other resources on Long Island, plus a new route to JFK Airport.






TOLLROADSnews 2007-11-26

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