ON THE BILEVEL. Transport Blog has some information about the electric commuter trains in Sydney, Australia. One of the most tempting but difficult things to do with a passenger coach is to fill up otherwise empty space with additional seats. Sydney's railroad attempts to put two levels of seats in a standard-height passenger car. That's not easily done, although the Long Island Rail Road and the Southern Railway (of England) operated such things, the Long Island's for over 20 years. (The new sets of double-deck cars on the Long Island are something different.) Metra Electric, the old Illinois Central electrification, manages to do the job with motorized cars with interiors similar to the gallery coaches in use elsewhere in Chicago, but with a lot more vertical clearance than your Commonwealth or East Coast railroad has to work with. The cars run on 1500 volts D.C., advanced for late-1920s electric traction, as does the connecting South Shore Line, which still offers riders the interurban experiences of flagging down the car with a lighted newspaper and of using the middle of the street for a station stop.