The two choices considered for the new tunnel connecting the 63rd Street East River tunnel to Grand Central are the "semi-deep" and "deep" options. Under the "semi-deep" scenario, LIRR trains would run into the terminal in a new tunnel directly below the existing Metro-North Park Avenue tunnel. The over-under proximity would require significant undergirding of Metro-North's tracks, causing significant construction impacts on regular MNRR service. It would also impact buildings along Park Ave., 53rd St., and 55th St., including taking commercial space for site access. Although sending the tunnel deeper would mean blasting through the bedrock seventy feet below the existing tunnel, the "deep" option is projected to cost $400 million less because it avoids these extra costs.

Whichever tunnel option is chosen, the documents confirm that LIRR service to Grand Central will create transportation challenges for both Long Island station towns and transit Manhattan's East Side. LIRR believes that due to the new service, most rail stations in Nassau and Suffolk will receive between 20 to 70 more auto trips during peak hours (200 more for Ronkonkoma). These extra cars will further pack already tight station parking lots. Discussions of strategies to counter this crowding seem to have been limited thus far to pouring more asphalt and raising more parking decks. Towns should consider investing in jitney or bus services to bring commuters from homes to stations, and improving pedestrian and bicycle station access (see MTR #254).

More LIRR riders will also further exacerbate elbow-in-rib conditions on the Lexington Avenue line. The hardest hit subways will be the southbound #4 and #5 trains, where an additional 1,800 passengers are expected during morning peak commutes, and the northbound #6, that will add 700 additional passengers. Over the entire morning peak, the Lexington line may be forced to carry 7,300 more people, raising its level of over-capacity from 112% to 117%. In fact, these numbers may be low, as the LIRR also plans to reduce the number of Atlantic Avenue trains from 16 to 10 once they begin routing trains to Grand Central. Riders who usually travel to Atlantic Ave. and transfer to lower Manhattan-bound subways there may end up at Grand Central instead, and further pack the Lex.

The memos reveal that NYC Transit is considering addition of another express train to Lexington line service during the morning rush hours, which - according to previous statements made by the agency - would require expensive signal and interlocking improvements. But one extra train many years hence seems like weak medicine for East Side riders already jammed beyond tolerable conditions.