More trains on crowded Expo Line may not solve the problem

The new Expo Line section to Santa Monica has become so popular and crowded, some passengers are reporting they can’t fit on the train and have to wait for the next one.

But adding more trains may only provide temporary relief.

The Los Angeles County Metropolitan Transportation Authority's train car shortage dates back to contractual delays when the agency ordered the cars years ago.

New cars are now being delivered, although they still have to be tested before they can carry passengers. Metro has received 41 new cars and is still testing 13.

Officials said with new cars in circulation, they should be able to reduce the time between train arrivals from 12 minutes to 6 minutes by December.

Until then, passengers will see shorter trains and longer waits, resulting in overcrowding during peak times on the Expo Line.

But transit planning consultant Jarrett Walker, author of the book and blog Human Transit, warns even after new trains are added, passengers shouldn't expect the overcrowding to be permanently resolved.

"What actually happens when you put out more service or relieve the crowding in any way is that more people start riding and so the crowding comes back," he said.

Once word gets out that overcrowding has eased, more people decide to use the trains. He said the phenomenon is also seen on crowded freeways.

Take the 405 freeway. Even after it was expanded, congestion wasn't fully relieved. Similarly, popular train lines will support as much crowding as people will endure. 

One dramatic example of this is the packed trains of Tokyo, where platform attendants literally stuff crowds through the doors.