driving along a wide smooth highway is something we all enjoy but building a highway is a big job it takes many man a lot of machines and a lot of materials first of all men have to decide just where the highway should go they have to measure the land and mark the path the highway is to follow that's what these men are doing their survey hours after the surveyors finish their work other men clear the ground they cut down trees that stand in the way and they burn and then come the machines first and the mighty bulldozers it's work is to make a wide path or trail for the highway this machine can move tons of earth along at a time the driver moves a lever and a wide steel blade drops down other levers makes a big machine move ahead it would take dozens of man to do the work this machine is doing the bulldozer moves along it pushes the earth ahead of it over the bank goes the earth from the hillside making a good wide trail this is done so that even bigger machines can take up the work giant road scrapers go into action the tractor has caterpillar treads on its wheels so it won't get stuck in the loose deep sand the huge rubber tires on the scraper help keep it from getting stuck to one big tractor is pulling this scraper and two others are pushing it scraper like this acts like a giant shovel that scoops up the earth in great buckets for the big scraper buckets soon fills with air and when it is full to the top the tractor p away to a low spot so the earth scrape from the hillside goes to fill in low places in the road so now the land has been cleared and a level roadway has been made next we will see how the roadways paid to begin with workman's set up a heavy steel track along each side of the road big steel stakes hold the track in place these tracks will hold in the wet concrete until it hardens also the wheels of the paving machine will run on these tracks now the road gets a final leveling to make it ready for the concrete painting any high spots that still remain had to be leveled off and any low spots had to be feelin it would be wasteful to use concrete to fill in the low places high spots would leave the pavement thin and too easily when heavy traffic runs over it now the road is already to pay with concrete while all this is going on another part of the job of road building is taking place nearby here more big machines are getting ready some of the materials needed for concrete pavement truckloads of rock and sand are carried to crushing and screening machines crushing machine breaks up the big rocks the screening machine separates the sand and the small rocks two sizes of rock are often used to make concrete paving this is one size but it takes other materials to make concrete one of these is cement here cement from railroad cars is clo d into the elevator and dropped into the paving trucks each load of paving material gets the right amount of the gray powdery cement we need sand too to make concrete small rocks and clay have been washed out of this sand down from the hopper drops the sand into the truck it falls on top of the cement and rock already there now the paving truck has a full load of paving materials the driver heads it out toward the highway where the paving machine and a crew of man are working the paving truck backs up to the front of the paving machine and on the large scoop paving men call it skip the paving materials fall into th little pounding loosens any samandar sand that sticks in the truck water trucks haul in the water to make concrete the water runs out of the truck and into a pump on the side of the mixture the pump forces the water on into the the mixture man watches everything going on around the paving machine at just the right time he moves in levers and up goes the scoop with another  into the mixer drops the batch of raw materials or spins round and round until all of the water sand rock and cement they're mixed into concrete this big bucket carries the mixture along to the right place and dumps it at once men begin to spread it out over the road heavy wire screens help strengthen the center of the pavement this wire will help keep the center from cracking after the pavement drives more and more concrete goes into place on the road bed this machine cuts grooves across the pavement put a strip of heavy fiber in each group this will help keep cracks out of the pavement later on machines do most of the leveling but the final smoothing is done this way roughing now will help stop the glare of light shining off the dry pavement later rounding with  trowel will keep the edges from breaking now it's time to cover the paving the man what it down and cover it with heavy paper all of this makes the concrete dry slowly and that's a good thing because slow drying helps make strong concrete now the concrete paving is finished but the highway is not yet completed later on we find guardrails alongside grades incurs in stop signs and stop and go lights to print cars at crossroads now the roadway has become a highway leads into other larger highways i ways that join together all parts of our country highways that let us travel quickly and safely if we're careful where ever we want