Show BUILD HIGHWAYS TO SUIT AUTOS tor for a long time highway anle insisted that motor vehicles should be adapted to the highways but now the highway departments are trying to adopt adapt the highways to tile tho and tho the asserted prof T it II agg of tile the highway engineering division at iowa state college and chairman of fl conin committee lIttee of the highway research board of the national research coun ell cil ot at a recent meeting of the metro politan section of tile tho society of automotive to Hugin cers in now new york limitation of loads and of sizes of vehicles must necessarily continue us as it a safeguard to the existing investment in highways hut but regulations in this regard are made na as liberal as conditions i ilow how tile the new conception of tile the function f highway g w systems r t m s has triad it int ini ahl that sd highway engineers obtain t n f a t clear c ae r understanding u e rs tan ding of the interrelation torrel ter relation atlon of the highway and the vehicle that la Is the reciprocal effect of tile the road a and nd tile the vehicle upon each other low end and intermediate types of road surface wear tires from four to ten tell times limes faster than high typo type toad road sur faces and surfaces of loose angular atone may produce prod tice 20 times the wear on tires caused by high type surfaces tho the most economical road grade as a general principle said bald professor agg age Is ono one that will allow a vehicle to ascend in high gear at tile the most eff lelent engine speed and to descend without the uso use of brakes and without attain ing excessive speed tho best typo type of car road tor heavy la Is a concrete road 12 inches thick that hat lias has about forty pounds of steel reinforcement in each square and with the tha slabs laid in lanes innes about ten feet wide so BO articulated that more lanes can he be added if needed ant and with expansion joints eints every 35 feet on heavily traveled roads 6 each foot of distance saved will ivill justify nn an ex cx of at least 00 and tins tilts should bo be borne in mind when tho the shortening of distance entails heavy grading or other expense when a road grade requires the shifting of gears and excessive use of the tha brakes br aises extra cost for gasoline and tire wear will result and can bo be estimated tills this extra cost however may bo be less than that of traveling the extra distance required to secure a lower rate of grade tho the cost of any type of road Is the aggregate 11 gg regate of the expenditures required to build the surface and to keep it in a condition of maximum serviceability over an indefinite period of years |