In April 2006, the MBTA agreed that it would spend approximately $310 million over a five-year period to upgrade their transit system to become one of the most accessible in the country to disabled riders. This is stemming from a class-action lawsuit against the MBTA under the Americans with Disabilities Act from 2002. C&C Consulting Engineers was retained as a part of an interdisciplinary team to perform surveys of six subway stations in Boston and Cambridge, Massachusetts. The stations were at Park Street, Harvard Square, Porter Square, Downtown Crossing, State Street, and Symphony Hall.
At each station, a closed traverse was established in accordance with the MassHighway Survey Manual Second Order Class 1 standards. The traverse would begin at the surface level and descend up to three levels to the lowest portions of each station. On each level, accurate horizontal and vertical temporary benchmarks were established to set the floor elevation and horizontal placement of each level. Once the traverse survey had been checked and balanced for minor errors, a detailed survey was conducted specifically in the areas of each floor where the proposed elevators were to be constructed. Existing conditions base plans were plotted using AutoCAD software with color-keyed plans that distinguish each individual level of the station on one drawing sheet. The plans include a grid to establish bearings and distances accurately from level to level. These plans were used by the architects to conduct alternative analyses for the placement of the elevators at each station.
Once the concepts were evaluated and one scheme was chosen, we returned to the station to conduct a detailed survey of the exact location of the proposed new elevator. Laser technology was used to set up a three-dimensional reference system from which measurements were taken accurate to the nearest eighth-inch.