THE CONSTRUCTION AND OPERATION OF AN EXPERIMENTAL ROAD- HEATING SYSTEM IN AN UNDERPASS ON KINGSTON BYPASS, A.3, SURREY

THE HEATING SYSTEM ON THE KINGSTON BY-PASS, A.3, SURVEY, WHICH COVERS AN AREA OF 4480 SQ YD AND HAS AN ELECTRICAL LOAD OF 372 KW WAS CONSTRUCTED AT A COST OF 10,828 BRITISH POUNDS. THE OPERATING COST PER WINTER AVERAGED OVER THREE WINTERS WAS 18.2D/SQ YD. DETAILS OF THE SYSTEM AND THE PAVEMENT CONSTRUCTION ARE GIVEN. THE SURFACING OF THE ROAD WITH ROLLED ASPHALT WAS COMPLETED WITHOUT APPARENT DAMAGE TO THE CABLES BUT SUBSEQUENT TESTS HAVE SHOWN THAT A HIGH PROPORTION OF THE CABLES HAVE AN UNSATISFACTORILY LOW INSULATION RESISTANCE.