Regardless, the NY Second Avenue Subway and LA Westside Subway are the most important and worthwhile transport projects in the US currently. I just hope their costs and timelines can be kept under control.

But the LIRR riders actually will be only a block or so from a Second Ave connection, depending on how the elevators and escalators are placed.

One day many LIRR riders may be heading far downtown to Wall Street area jobs. In this way the SAS may eventually divert riders from the West Side subways serving Wall Street. They will need more room when the added passengers start coming into Jersey Transit’s own deep station under 34th St near Sixth Ave.

I’m with Alan that Phase 3 and Phase 4 of the SAS are really something for the sweet by and by. But if or when, they could stimulate more riders on the LIRR.

I really didn’t mean to get into that issue however. I was just trying to round up assorted reasons why I’m skeptical of the claim that the full $17 Billion SAS line would only draw 11,400 new transit users.

BTW Everything Alon said about Upper East Side population concentration is true. But let me add a couple of things. Both Fifth Ave and Park Ave (a.k.a. 4th Ave) are lined with pre-World War II apartment buildings. The spacious, high-ceilinged apartments typically are occupied by the VERY rich, often Mr and Mrs and a live-in servant or two, and thus lower population density. Zoning limits the height of new buildings, and current valuations also limit redevelopment.

Then the El came down and beginning after World War II, tall and taller apartment buildings began to line Third, Second, First Ave, and even York and East End. They are typically much taller than those on Fifth and Park, and their residents are the working rich — very high-income professionals — in smaller apartments, or shared bedrooms, and thus considerably higher density. Two-bedroom apartments and four or more stewardesses sharing was once the stereotype. And public transportation in this section actually includes three or four guys in pinstripes sharing a cab to Wall Street.

I’m as distressed as anyone at the cost and delays of the SAS. But I still think it is well worth doing. And it will attract a lot more than 11,400 new transit riders, for sure.

Anon256: Second Avenue is closer to the densest areas of residence on the East Side. In fact, the Upper East Side’s center of population is on Second Avenue somewhere in the high 70s or low 80s, due to the importance of Second and Third Avenue El when the area first developed; the Lexington Line serves a lower-density area.

ESA riders will take the 4/5/6, but many residents of the Upper East Side will switch to SAS, which will not only serve East Midtown faster but also serve the West Side through the Q.

And I just don’t believe that number of added riders applies to the full $17 Billion plus project. That might be the number of new riders estimated for Phase 1, where population is very dense and the use of public transportation is high. If that’s the Phase 1 estimate, it may turn out to be another example of a low-ball figure due to the hostile methodology imposed on transit funding applications.

Then Phase 2, from 96th St north to 125th St., will run through an area with many low and mid-level buildings, and lots of vacant lots. It also has many, many lots occupied by what the real estate industry calls “taxpayers” — one-story retail on land being held for future development.

When the SAS is extended north, and this area becomes the “Upper Upper East Side”, scores of high-rise apartment buildings will spring up along the avenues. From the new residents alone there’ll be 10,000 new transit riders.

Phase 3 may come along after the East Side Access project starts bringing Long Island Rail Road riders into a new station beneath Grand Central Terminal. With the new route adding capacity, and freeing up capacity at Penn Station, it seems quite possible to me that ridership on the LIRR could soar by more than 11,400, with most of those ultimately transferring to the new SAS line.

Wrong metric. It’s there to relieve dangerous overcrowding on the Lexington Avenue Line — and to give the people currently commuting by bus (also overcrowded!) a route of reasonable speed. For those purposes it does pretty damn well.

Although it is costing more than it ought to.