LIRR Bridge Replacement at Post Ave

McLaren Engineering Group provided bridge engineering design services for this $9.7 million LIRR bridge replacement project at Post Avenue in Westbury, NY. As part of the Long Island Rail Road (LIRR) upgrades, the Third Track project was approved to add a tertiary track to 9.8 miles along the congested Main Line of the LIRR between Floral Park and Hicksville. The first completed project initiative since the Main Line Expansion Project has been the Replacement of the Post Avenue Bridge in Westbury, NY.

Originally built in 1914, The LIRR Post Avenue Bridge was a 63-foot single span structure carrying two tracks supported by steel thru plate girders with a concrete deck and reinforced abutments made of concrete. The 100+ year structure has been a conduit for train traffic that cars and buses pass under with an original roadway clearance of only 11 feet 10 inches. The dimensions had made it extremely vulnerable to vehicular strikes, particularly from trucks failing to clear the underpass. Although still considered in good condition, the bridge was struck over 80 times, causing numerous train and roadway delays in both directions.