War On Wet Weather Accidents (1974)

foreign to all but the smallest of us it's nothing new and certainly nothing to be feared [Music] and yet it affects our lives in many different ways it can be at one and the same time pearls on a petal or rivalence of Danger on our roads and highways [Music] when rain falls the battle on the highway in rain slick highways are every driver's enemy any roadway situation that causes a driver to make abrupt maneuvers [Music] the hazards of other cars and roadside structures can become almost invisible until when it is too late for a life-saving reaction drivers know that wet weather driving is dangerous they know that roads are Slicker When Wet but few take the necessary precautionary measures [Music] the result [Music] the wet weather accident rate is often 10 times that of the dry weather rate look [Music] in a concentrated effort to reduce the toll of wet weather accidents Engineers of the Texas Highway Department the Federal Highway Administration and the Texas Transportation Institute are conducting extensive studies to determine ways of reducing wet weather accidents [Music] thank you [Music] [Music] [Music] [Music] what causes wet weather accidents [Music] what is the role of the driver the vehicle and the road in these accidents drivers due to combat wet weather accidents answering these questions is the goal of research [Music] tests prove that when identical Vehicles buy Pavements the stopping distance can double on the wet surface [Music] what makes the difference it is the change in the capability to develop forces between the tire and the road surface [Music] in defining this change the influences of rainfall intensity Tire factors and Road surface characteristics are critical [Music] one way of measuring these influences is by using a skid trailer this skid trailer tests the friction between tires and road surfaces the friction is measured by locking the brakes on one wheel of the trailer thank you [Music] the friction force that is generated between the tire and the wet pavement is then measured electronically a range of test surfaces has been constructed at Texas a M's Highway Safety Research Center the coarser the texture of the pavement surface the greater the frictional force surfaces lower the grip of the tires on the road in determining tire and pavement influences a Rainmaker is used to simulate different rates of natural rainfall [Music] drainage conditions affect the friction capabilities of both coarse and smooth Pavements a coarse textured pavement surface with an adequate cross flow for drainage provides the best driving surface during wet weather when it is raining a smooth Road surface and poor provision for drainage May reduce Tire pavement friction to a dangerous level [Music] another aspect of this work is to determine the polishing characteristics of Highway surfaces traffic polishes a road surface and slowly decreases the capability to develop friction many roads which had excellent friction characteristics when built have been Polished by millions of vehicle passes until they are very smooth by subjecting different Highway surface materials to the simulated action of traffic the best constituents for pavement construction can be identified [Music] two methods are used to determine the changes in surface materials due to simulated traffic the first is a direct friction measurement using this standard pendulum device the more the friction the lower the pendulum Rises after sliding on the surface [Music] the second method which gives information on what is actually happening to the surface is the stereoscopic microscope examination thank you however good friction does not solve all of the wet weather driving problems during or just after a hard rain water May collect on the road despite good drainage slopes even during light rain puddles may form in the wheel paths worn by traffic in either case vehicles moving through these water accumulations may be subject to hydroplaning what is hydroplaning when a tire rides up on the surface of the water like water skis on a lake [Music] the tire is hydroplaning when an automobile Tire rolls at a low speed over a surface covered by a layer of water the tire squeezes out the water and makes contact with a road surface as the speed is gradually increased a critical speed is reached where there is not enough time to force the water out from between the tire and pavement the tire then rides on the water which results in loss of contact with a road surface this can be seen because the tire spins down and stops when this occurs the driver has no steering control and brakes will have no effect on stopping [Music] a hydroplaning trough and an offset towed trailer are used to study hydroplaning foreign s High tire pressure and rough road surfaces help disperse the water between the tire and the pavement and reduce the risk of hydroplaning however these experiments have shown that hydroplaning can occur on good road surfaces at speeds less than the legal limit poor tire and road conditions can result in hydroplaning at speeds as low as 40 miles per hour a fourth part of the current research is devoted to the automobile what are the wet weather handling characteristics of different automobiles [Music] for example is this Volkswagen safer or less safe than this Ford [Music] answering questions like these requires the consideration of many factors and the answer may very well be different for different drivers by subjecting a variety of cars to a series of safety related Maneuvers these answers are being sought but what is being done now to reduce these hazards because of information from research the state legislature has recognized the disastrous effects that poor tires can have on wet weather driving our legislators have enacted a state law requiring the maintenance of a minimum tire tread depth of 1 16 of an inch improved construction and maintenance practices are being rapidly implemented by Highway engineers [Music] better surface drainage is being provided roadway geometrics are constantly improved skid trailers are operating across the state to identify hazardous sites that may be developing due to the polishing of traffic A New Concept of wet weather speed zoning is under investigation which can be used in the interim before physical changes are made on the roadway a variety of other signs are now in use to provide motorists with warnings of dangerously wet Highway sections these signs are not placed without good cause and should be acknowledged by lowering speeds however no matter how many improvements are made in highways and Automobiles the accident rate will decrease only slightly unless there are significant changes in driving habits the most important element of safe driving is the driver he must maintain control over the vehicle in a hostile environment he is the Ultimate Warrior against wet weather accidents of critical importance is visibility in Rain the higher the speeds the more limited the driver's vision the wipers cannot work fast enough to keep the windshield clear the time a driver has for defensive Maneuvers is critically diminished [Music] although a highway is designed to meet rigid standards for sight distance it cannot be designed for Blinded drivers by turning on low headlight beams you can help other drivers see you [Music] too often drivers do not compensate for the hazards of wet weather driving or feel so skillful they can compensate for slick roads and poor visibility this is a most serious mistake in judgment [Music] drivers must recognize rainfall as a formidable enemy and exercise a definite strategy to win the battle against wet weather accidents summarizing the specific precautions a driver can take first keep alert be aware of the road condition indications of danger include puddling in the wheel paths and a slick looking glossy Highway surface [Music] speed must be reduced if a surface looks dull and rough it probably has good traction qualities even so speed must be adjusted for visibility second tires should be checked often they need deep tread and maximum tire pressure [Music] the maximum pressure recommendations can be found on the side of every Tire if there is a significant layer of water on the road surface speed should be reduced to 40 miles per hour to assure that hydroplaning cannot occur third visibility limitations must be respected each driver should maintain windshield wipers and turn on low headlight beams [Music] it is important that you see other drivers and it is equally important that they see you speed must be reduced in proportion to reduced visibility finally whatever the wet weather conditions may be the safest measure any driver can take is to slow down allow more time to think and react to any hazardous situation that might develop yes rain may be necessary to our lives in many ways but its presence is a threat on the highway research can provide the answers needed for safe wet weather travel But ultimately only the driver can provide the solution there is a war on our highways it has taken more lives than all our other Wars combined when will we decide that too many lives have been lost the answer my friend is in your hands foreign [Music]