The Highway Signal No. 154 was the accessory that is most closely associated with Lionel Post War electric trains. This is because it was produced throughout the entire post-war period from 1945 until 1969. As out of scale as it is, this is the one accessory that was almost always found on toy train layouts of the period.

With the use of the No. 154C track contact this signal would flash its lights in warning as a passing train conducted the ground current through the outside rails.

There are a total of five variations to this signal. The first two involve the cross sign. Early issues were made out of metal (A Variation), but those that followed would be plastic (B Variation). In 1950 Lionel issued limited amounts of this signal with a RED or ORANGE base, some of which were only painted on the outside (Variation C & D). This version is shown in the catalogs up to two years later. The last variation has the post made out of aluminum instead of sheet metal.