Something I've been curious ever since I first heard of aspirations to spend $7 billion renovating Union Station in Washington, DC is the assertion that the current configuration of platforms isn't compatible with the Americans With Disabilities Act. Nobody seemed to have specific statutory or regulatory language on train platform widths they could cite me, but it's clear that a lot of people involved with the project are under the impression that there's a major accessibility issue here.
Those people might be interested to read the National Disability Rights Network's generally scathing report on Amtrak accessibility issues (PDF) which finds that Union Station is one of the elements of the system with the least problems. Here's their full report on DC:
Twenty five years ago Union Station was restored and rededicated as a train station after an ill-advised attempt to make it a visitors center. P&A staff found it to be mostly accessible. However, access to the platform serving tracks 27 and 28, which serve trains going south to the Carolinas and Florida and other southern destinations, continues to lack an elevator. Thus, passengers heading south or detraining from trains using tracks 27 and 28 must wait for carts operated by Amtrak personnel that take a circuitous route out along uncovered portions of the platforms and crossing tracks to get to and from the station.
This is obviously an undesirable state of affairs, but in the scheme of things it's a quite modest concern. The tracks in question are serving a relatively small share of the station's passenger traffic (which is overwhelmingly heading north to Baltimore, Philadelphia, and New York) and the problems seems fixable with a relatively modest intervention. The NDRN is not shy about calling out problems at Amtrak facilities, and simply doesn't seem to be raising this track width issue.