The Aurora Plastics Corporation of Long Island, New York was a dominant manufacturer in the early years of slot cars. In 1959, Aurora obtained a license from the Crafco Corporation to produce an electric car system designed by Derek Brand. The system featured cars powered by a small vibrator motor operating on slotted plastic track. Crafco had originally licensed this design to Playcraft Toys Ltd. in the UK.

Playcraft marketed the system as "Electric Highways Model Motoring" from 1959.

These sets were originally intended as a 1/76th scale highway system to complement British "00" gauge model railways (i.e. 4mm to the foot scale and not 3.5 as the railway system). Poor sales in England had Crafco looking for a USA manufacturer, resulting in the license to Aurora. In January 1960, Aurora began marketing "Highways" as an "HO" scale highway system, even though the cars' size remained the original British "00" gauge (1/76th scale) used by Playcraft. For more information, see the excellent "Greenberg's Guide to Aurora Slot Cars" by Thomas Graham and The Toybaron's website. 

Soon kids everywhere found that it was much more fun racing these cars instead of using them as an add-on to model railway layouts. Aurora quickly recognised this phenomenon and began marketing the sets with a racing theme. In the autumn of 1960, the "Highways" name was dropped and Aurora began marketing the sets using the original Playcraft "Model Motoring" name. The new marketing strategy proved to be an instant success. There's more information about Aurora model cars here.

The Playcraft 'Electric Highways Model Motoring' roadway system was introduced in 1959. See the catalogue(s) here

Cars have been seen with both steel wheels and plastic wheels.   Some later Ford Lorries came with a payload that looked like the core of a roll of tape and was copper coloured. The track came in various sized 9 inch pieces and a few additional track pieces were also manufactured. 

Before operating the set it was necessary to assemble the track and insert the copper conductor in a slot in the plastic road.

The following is a list of what was available - click the picture for a bigger image or on the link for more info.

 I also found the following article in an issue of the Model Railway Constructor from 1962

The article compares the Tri-ang Minic Motorway system and the Playcraft system.

The Chevrolet and Ford truck are now much sought after and can command over £300 each! A No:1 set with these vehicles recently sold at auction for over £700.