Rail transport is recognized as the most sustainable means to move people and goods. Alcan's contribution to this development was to make such trains lighter by replacing steel with aluminum. Today, approximately 80% of passenger rail cars are built of aluminum – even the cars of Shanghai's advanced Maglev (magnetically elevated) Transrapid train were designed by Alcan.

An independent study has shown that each kilogram of weight savings of a train means an average savings of greenhouse gas emissions of about 80 kg for short distance trains and about 48 kg for long distance trains, calculated over the trains' useful life of 30 years or more. This is in addition to other environmental savings such as energy resources.

Compared with the steel alternatives, a long distance train car is typically four tonnes lighter when built of aluminum, which means that it saves 192 tonnes of greenhouse gas during its useful life. A short distance aluminum train car is two tonnes lighter than the steel alternative and saves 160 tonnes of greenhouse gas during its useful life.