Keystone, as the chart demonstrates graphically, is indeed "XL". Keystone's estimated volume per day of 830,000 barrels is equivalent to 1,383 rail cars! Projected capacity dwarfs rail car capacity which is much more expensive. Experts believe alternative transportation methods such as rail will economically constrain exploitation of the tar sands deposits and consequently reduce the amount of CO₂ entering the atmosphere from this fossil fuel source.