RE “ENVISION Longfellow not just as a bridge, but an amenity’’ (Editorial, July 29): While there are legitimate concerns that both state and LivableStreets Alliances proposals try to meet, the assertion that most bridge users are in motor vehicles is untrue if it refers only to autos, as the editorial implies.
The Boston Globe reported two years ago that “the Longfellow carries roughly 87,000 weekday passengers on the Red Line, plus 49,500 vehicles and an undetermined number of pedestrians and bicyclists.’’ In 2007, vehicle occupancy rate on the Southeast Expressway, which includes an HOV lane, was 1.36. Simple multiplication using this generous rate puts the estimated passenger throughput by auto at 67,000. Moreover, ridership has increased on the Red Line.
The key contribution of the LivableStreets Alliance plan and of the editorial is not to focus on what is, but to cast our eyes toward an alternate, better future. With the completion of the Central Artery/Tunnel, there may be ample room for drivers currently using the Longfellow to use the expensive infrastructure built in part to relieve traffic.
At the same time, ensuring that this plan does not impede the functioning of Massachusetts General Hospital is essential, and it is this element that needs the creativity of our local professional and academic community, and most of all, our informed citizenry.
David Block-Schachter
Cambridge 
