An Environmental Impact Report (EIR) is a document that attempts to describe the significant environmental impacts of a project (defined to include things like traffic and noise). A new EIR just came out for Phase II of the Exposition Blvd. Light Rail Project, which is slated to go from Culver City to Santa Monica.
What's the debate about? Grade separations: whether the train runs partially at street level intersecting periodically with traffic, or whether it will be completely above or below ground. Check out the debate at
With FEIR In-Hand, Expo Phase II Seems Ready To Roll, But Is It?
Expo Releases FEIR For Phase II Choses Alignment Along ROW and Colorado Ave.
The short version of my opinion is that at-grade rail is too slow, too dangerous, and too noisy for the people around it to be a good strategy for LA transit. We need subways, or at the least, elevated trains with sound walls. This is more expensive, so we'll have to accept a smaller, but more useful system. I'm fine with that.