They have built ramps to support loading of passengers with wheelchairs. As you can see, the line through the Anaheim Station is double-tracked. A project is currently underway to try and double-track most of the Metrolink route from San Diego to Oxnard.
The photos in this slide show were taken in the mid-1990's by Steve Grande on his Amtrak travels throughout the nation. The size of the photos is purposely smaller as disk space was expensive and download speeds were slower at that time.