THE ROAD IN RELATION TO TRAFFIC REQUIREMENTS--MEXICO

THE AIMS FIXED BY MEXICO WITH RESPECT TO ITS DEVELOPMENT REQUIRE AN ACCELERATED GROWTH OF ITS HIGHWAY NETWORK; THE MAINTENANCE, DURING THE NEXT 10 YEARS, OF THE RHYTHM OF GROWTH OBTAINED DURING THE LAST DECADE WILL INVOLVE THE CONSTRUCTION OF 60,000 KILOMETERS OF ROADS, OF WHICH 45,000 WILL HAVE A TRAFFIC VOLUME OF LESS THAN 500 VEHICLES PER DAY. THE OROGRAPHICAL DIFFICULTIES, TO WHICH ARE ADDED THE LACK OF INVESTMENT RESOURCES, HAVE HAD THE EFFECT, IN MOUNTAINOUS REGIONS, OF PLANNING FOR SPEEDS OF 60 KILOMETERS PER HOUR, IN ORDER TO REDUCE THE COSTS OF CONSTRUCTION AND TO BE ABLE TO ACHIEVE THE DESIRED AIMS. THE HIGH PERCENTAGE OF ROADS ENVISAGED FOR TRAFFIC VOLUMES WHICH ARE HARDLY CONSIDERABLE AND FOR LOW SPEEDS HAVE REQUIRED A DETAILED STUDY OF THE ANALYTICAL NORMS IN ORDER TO OBTAIN A BALANCED PLAN. IT SEEMS THAT AN OPERATIONAL STUDY OF CIRCULATION ON THE ROADS, BY MEANS OF AN ANALYSIS OF THE CAPACITY AND THE SERVICE LEVEL CONSTITUTES THE BEST MEANS OF ARRIVING AT A RATIONAL PLAN. WITH THIS AIM, STUDIES HAVE BEEN MADE OF THE POSSIBILITY OF USING THE ANALYTICAL METHOD RECOMMENDED BY THE HIGHWAY CAPACITY MANUAL OF THE UNITED STATES WITH RESPECT TO ROADS ON WHICH THE TRAFFIC VOLUMES ARE FAIRLY SMALL; HOWEVER, IT IS CLEAR THAT CERTAIN CIRCUMSTANCES SERIOUSLY RESTRICT THE APPLICATION OF THIS METHOD.