Show n if I 1 L I 1 N experiment IN GOOD ROADS road to chevy chase text book lit concrete brick and stone exi ports peris are interested there la Is here a text book in concrete brick and stone atone tho the road to chevy chase built by tho the plans and under tinder the direction of the office of public roads of the united states and for or tho the eole bole purpose ot of informing the public publia and the members ot at congress interested in the improvement ot at the public highways upon the methods ana cost of construction types of roads adaptability ot of material and economy ot of maintenance thousands of 0 people travel over this road which Is built in many sections eions of different types every everyday over day and hundreds eds of 0 practical road builders from all parts part of the country have inspected it from time to time ilme and havo have lb aa V Q N sand and gravel piled on Sub grada ready for use britni concrete road chevy chase md marveled at the excellence of the work manufacturers who have supplied bituminous materials for or the treat meat ot of therond the road jond have detach detached eai idair for fo r athla service and i the traffic over the road has demonstrated under carefully observed conditions the relative value of the several types ot of road making up this great highway the chevy chase road Is experimental it con consists fists ot of different types ot of pavement bitumen bituminous ous macadam laid by the pene penetration fration method surface treatments of 0 water bound macadam asphalt lc surfaces on concrete foundations bituminous surfaced concrete plain and oil cement concrete and vitrified fied brick nit all of which are under dally daily observation by expert road builders to ascertain which of the types is best suited to the traffic and which Is condemned by practical test under the same conditions of climate soil rainfall test heat and cold and like traffic requirements it would be just the same to tho the office ot of public roads which has written this open book in concrete brick and stone whether any part of it or all parts of it ii should tall fall failure in materials used lit in construction in durability in cost in maintenance the test Is tile the thing road building Is a science now and efficiency Is tho the only test ot of quality in the stones used in ID the construction of the chevy chase road their specific gravity their weight per cubic toot their water absorption their percentage ot at wear their hardness and toughness are all determined by the most careful scientific tests patrolmen raen are constantly employed on this road to keep account of whatever do de feletti in materials and construction may develop and exact data as to io tho he cost of maintenance the chevy chase road was fortu bately placed for the reason that all ot at its hectic is of types have been subjected to precisely the same sort of at year in and year out and tho the section or type aya that has baa not stood the strain has bein bean as important an object lesson to road builders as the section or type that has bag maintained itself un derlicke der like strain tho the road as a whole ta is a great experiment conducted conduct edby by the most competent engineers to demonstrate the most practical things |