 It's pretty easy and a natural reaction to forget about traffic controls when we're concerned about the immediate job at hand Whether we're opening a manhole patching joints or filling potholes We want to get on with the job and spend as little time and effort as possible in Setting up traffic controls for our work site. My name is Matt Huber I'm a professor of civil engineering at the University of Minnesota and I'll be your host on this series of tapes related to traffic control for short-term work zones and while we're making Introductions, let's make sure we all have a common definition for a short-term work zone on a street or highway We're talking about an operation where it's anticipated the activity will be all done in one work shift Typically six to twelve hours or less in Most instances you'll be installing traffic controls for a work zone proceeding with the project at hand and Removing the controls a few hours later Under these kind of conditions There are a lot of seemingly good reasons why we don't need to bother with pedestrians or road traffic like We will only be on the roadway for a short time. We'll be out of here in an hour or There's not much traffic along here this time of day and then We're just working on the shoulder. We won't bother anyone over here Or we haven't got time to set up. We've got to keep going Sound familiar We all have a tendency to get right at the job and to spend as little time as possible on Setting up cones or barricades and signs that may be necessary It sounds like the buckle-up campaign from TV and radio But the punchline is the same No excuse is good enough We should put ourselves in the role of the driver and take a look at the roadway Just as it seemed from behind the steering wheel None of us like surprises We don't like to turn the corner only need to be suddenly confronted by a large maintenance vehicle directly in our path None of us are very happy when our lane suddenly ends without warning and There's no room to merge into that adjacent lane Drivers like to know what's expected of them in the vicinity of a work zone Can I park on this side of the street? Am I supposed to pass to the right or to the left of this road work? How do I know when it's okay to resume speed? Not only do we have to give drivers advanced warning We have to make it clear What's expected of the driver? Driving is a complex task under all conditions The driver has to be concerned with other vehicles and with pedestrians on the roadway The driver has to be concerned with traffic control devices and Especially here in Minnesota It seems that the environment plays a part too when we add work projects on the roadway We're making an already complex job even more difficult All of us need time to make a correct decision especially when the condition is unexpected or unusual and Unexpected or unusual pretty much describes many of the situations our activities create on the roadway We're creatures of habit when it comes to driving The roads and streets we follow to work every day are familiar territory We know every stop sign and signal every school crossing and every curve We know the road so well that we may not pay attention to the unusual conditions on the roadway Controlling the commuting regular user may present more problems than providing for the stranger on the roadway as stated in Appendix B the purpose of traffic control is to provide safe and effective work areas and to warn control protect and expedite vehicular and pedestrian traffic To accomplish this the respect of the driver must be earned by appropriate and prudent use of traffic control devices And it makes no difference whether we're talking about a long-term project that'll be underway for several months Or a short-term project that has a duration of one or two hours The drivers or pedestrians who pass by during the time we're on or near the roadway Need just as much help and protection as those persons passing through the all-summer project And of course we want to protect those persons working on the roadway just as much as we want to protect the public Even on a short-term job. We need that protection just as much as on a long-term job And let's take a look at a series of visuals That illustrates some of the kind of problems that can arise When we don't follow the correct procedures in setting up work zones A common problem is that a failure to provide advanced warning Even though we're only on the pavement a few minutes such as you see in this patching job It should be protected by some advanced warning signs Now here's another example in which the workspace has been outlined with traffic cones But under those circumstances again, we need some advanced signing A special problem occurs when we have an activity that's concealed by road alignment Here we have some work on the pavement. It occupies most of the lane But it occurs just around the curve and we have to bring our signing beyond that curve So the driver gets the advanced message Another problem is failure to tell the driver exactly what path to follow In this example, the only indication we have of what path to follow Is the absence of dirt on the pavement where previous vehicles have gone And pedestrians need just as much an indication of where their path is as do drivers And still another area of concern that has to do with conflicts with the work activity space The workman has to be careful to stay inside the work area that's been set aside You can't be stepping outside and expect drivers to observe the control devices And if we're locating work vehicles at the site We have to take advantage of the traffic controls that are in effect Put the work vehicle beyond the control devices not in front And arrow boards have a lot of visibility But it doesn't do much good when we park one of our vehicles in front of it And another concern is more long range and that's a poor housekeeping We have to be careful how we handle the signs Rough handling is going to shorten the life and cause more maintenance problems Cones are easy to carry and they can be readily stacked But don't do it in a manner such as to block visibility as you see here Failure to follow these procedures Can cause hazardous situation for the worker on the roadway as well as for the driver or pedestrian There's a series of guidelines that have been developed for traffic control and work zones These will be found in the traffic control devices handbook published in 1983 by the federal highway administration Much of the material in this book is based on part six of the manual of uniform traffic control devices Which has been adopted by the state of minnesota First keep safety of motorists pedestrians and workers as the top priority We should try to keep traffic conditions as nearly normal as possible And take the time to plan and install a traffic control scheme Sometime this may mean we spend as much time in traffic control efforts as we spend in accomplishing our work task and second We want to inhibit traffic movement as little as possible We should try to maintain the maximum speed that can be safely accepted While eliminating abrupt lane closures We should also provide enough room for work equipment and vehicles Inside of our work zone and then get the roadway open again just as soon as possible Third, we want to get a clear easily understood message to drivers and pedestrians That means we have to know the exact meaning of each control device or sign that we're going to use It also means that we have to resolve any conflict in meaning between existing control devices And those permanently in place For example, we may be closing a left turn slot Or a right turn channelized roadway All of the geometry the signing and striping may guide the driver into the closed lane We have to make a special effort to overrule the regular message during the duration of our project And sometimes flagging may be the only way we can properly assure getting the right message across fourth All devices must be kept in good repair and properly stored so that adequate visibility is retained Signs and other devices must be placed where they can be seen by the driver in time to make that correct decision And again As soon as the project is finished the control devices should be promptly removed Fifth and finally You should anticipate the increase in hazards that arise from your presence on or near the roadway Provide room for disabled or out of control vehicles Most of the devices that are used are lightweight and yielding so that damage to air and vehicles will be a minimum But be sure to keep equipment materials debris and yourselves, of course Where there will be a minimum of vulnerability from out of control vehicles We'll be expanding on these five principles in the following sections of this course In this section, we've taken a look at the reason for traffic control and the relationship to safety in work zones In the following material, we'll be reviewing the types and uses of traffic control devices The mechanics of designing and installing traffic control in a work zone And then we'll be reviewing some typical applications that you'll be using in your work In order to give a message to drivers and to establish a work zone We must have a method of delivering a message which is quickly recognized and used in the work zone Which is quickly recognized and understood Remember, too That the work zone is an unexpected happening And that the message must compete with the regular signing Markings and other devices that are normally present Traffic control devices are the most effective communication tool And the five basic requirements of such devices are found in part six of the manual Uniform traffic control devices Now first, the devices must fill a need We've already talked about the importance of getting the message to drivers at work zones Second, the devices must command attention There are many concerns of the driver Ranging from such things as tuning the radio Looking for an address Making a left turn against high volumes And watching out for the other driver The control devices have to override the competing activities in order to get the driver's attention Third, the devices must convey a clear simple meaning Often the driver has time only for a glance at a sign And has only a short time to decide what action is required Fourth, the device must command the respect of the driver The driver has to feel that the message is to be followed And not simply an alternative action that may offer another opinion Fifth, the device must give adequate time for proper response We can do this by making devices highly visible And placing warning devices in advance of the work zone A series of devices that meet these five requirements Have been jointly developed by the state and national transportation agencies The devices have been standardized so that all government agencies will use similar devices The standards are published in the Minnesota Manual of Uniform Traffic Control Devices Which also includes the Standard Signs Manual These are the same standards which are used in work zone controls The most commonly used devices for work sites are signs and channelizing devices Signs are used to advise and warn drivers And to instruct them as to how to proceed through the work site Channelizing devices are used to guide the drivers through the site To indicate hazardous areas and to keep traffic out of the actual workspace The channelizing devices themselves may become hazards So that advance warning signs must always precede their use The standard colors used for signs are shown here The public has come to recognize the message based on color only Red for stop or prohibition Yellow for general warning or blue for motorist services In particular, the color orange has been assigned for construction and maintenance signing Shapes are also used to communicate a message The use of the octagon for the stop sign Or the circle for the railroad crossing are easily recognized While most drivers readily react to the diamond shape used for warning signs Signs are listed in three categories Regulatory signs, warning signs, and guide signs Commonly used regulatory signs are shown here While they are not frequently used in short-term work zones It is well to recall that these signs impose legal obligations and restrictions on all traffic This means that their use must be authorized by the public body or official Having jurisdiction and that the signs conform with the manual on uniform traffic control devices If a project would require the closing of a right turn channelized lane With a subsequent change from a yield to a stop sign It would require advanced arrangement with the proper agency Regulatory signs should be located at the point where the regulation or law becomes effective For example, parking restrictions begin at the point where the sign is located Any existing regulatory signs which are overridden by the temporary regulation Must be removed or covered to eliminate drivers confusion Warning signs are diamond-shaped with a black message on an orange background These signs are used to warn drivers of potentially hazardous conditions They should be used when such conditions are real Particularly when the danger is not obvious or cannot be seen by the driver Typically, warning signs are placed far enough in advance to eliminate drivers confusion Warning signs are placed far enough in advance of the hazardous conditions That the driver has time to take in the message and take any required action For high speed application, all signs shall be at least 48 inches on each side Guide signs with particular application related to work zones are shown in this view Their particular use is to define the beginning and end of a work area And to mark temporary detour routes As for warning signs, these are a black legend on an orange background Consider these items when choosing signs Choose signs that are appropriate that accurately describe the work situation The message should agree with the action the driver needs to take Local messages may not be clear to strangers Start with the same sign For example, road work ahead on every project And then become more specific as the driver gets closer to the work area Recognize that distances in urban areas can be restricted by the length of city blocks Or entrances to alleys or shopping centers On high speed roadways, there's a need for greater warning distances and larger signs On one way streets or roadways with mediums It's advantageous to place signs on both sides of the roadway Also, make sure that signs are high enough so they can be seen over parked cars or heavy traffic And that they're in a position not blocked by vegetation or by work activities If traffic is heavy and backed up, it may be necessary to extend the advance warning area Beyond the end of that backup Care must be taken that signs don't block the view as the driver enters the area We'll cover details of sign placement in greater detail in the next session Now, channelizing devices are placed in or adjacent to the roadway to control the flow of traffic They have two distinct purposes First, as a taper to force movement of traffic from one lane to another And then to delineate and guide the driver to and along the safe travel path The several different types of channelizing devices are shown here Each with its own characteristics and advantages Traffic cones are an effective method of channelizing traffic along a path during daylight hours The devices don't damage vehicles when hit and they're easily recognized by drivers They're easy to store and can be quickly put in place on the roadway Because they are lightweight and because they're small They're easily knocked down so that monitoring is necessary to keep them in place Drums serve many of the same functions as cones But drums appear more formidable than cones and they command more respect They should not be weighted to the extent that they become hazardous to drivers Currently, drums are made of plastic materials that are less likely to be damaged when hit And they won't roll if tipped over Barricades are also used to outline work areas Close or restrict the right-of-way Channelized traffic or as sign mounts Barricades are placed so that the diagonal stripes slope Toward the side on which traffic is going to pass Types one two and three Differ only in the number of rails on the barricade The more rails the more visibility But also the more rails the heavier and more awkward the device becomes Like drums Barricades command respect and they are observed by drivers Sandbags are the only ballast permitted on barricades And that they may only be placed on the base Unlike cones and plastic drums Barricades are likely to damage vehicles if they're hit Vertical panels are used for traffic separation Or shoulder barricading where space is at a minimum The application you see here is on an elevated freeway Where there wasn't enough space for conventional barricades Still another device are the warning lights that are used for work that continues beyond daylight hours Or for unusual conditions where they may be an abrupt change in the driver's path Flashing lights are used in the advanced warning area And where there are unusual conditions such as were previously discussed It should be emphasized that flashing lights should not be used to outline the driver's path Their use in those circumstances would be confusing Steady burning lights that's type c are used to delineate and outline the desired path Now high intensity flashing lights Otherwise known as type b are available for daytime applications While low intensity flashing lights type a Are visible only at night Advanced warning arrow boards are intended to supplement other traffic control devices That we're using in the work area While these devices won't solve difficult problems by themselves They are effective when used in conjunction with the signs Barricades cones and other devices There are three types of arrow boards The principal difference is in the distance at which the boards can be seen Type a with a visibility distance of one half mile Is recommended for low speed urban streets While types b and c are recommended for high speed highways The arrow board is intended to be placed on the shoulder Near the start of the taper and is not to be centered in the closed lane Flashing lights on work vehicles are also part of the series of devices used to control traffic The vehicle warning lights may be emergency flashers flashing strobe lights Or rotating beacons Finally High-level warning devices are often used in urban high density traffic situations To supplement other traffic control devices High-level devices are placed inside of the channelization And in the center of the blocked traffic lane While usually mounted on a flag stand The device may also be attached to a service vehicle When the vehicle is placed in advance of the work area This concludes our brief review of traffic control devices Any particular details will be found in the minnesota manual of uniform traffic control devices And in section four of appendix b In the following tape, we'll be taking a look at more details about the applications of these particular devices In this segment, we'll develop location and placement criteria For those devices that are used at highway and roadway work sites These criteria will be the basis for the particular applications that we'll be illustrating in the next course segment And when we talk about dimensions, we're talking about minimum standards And those dimensions, if they are to be changed, should be done so as to make things safer For example, the spacings recommended for signs are minimum values because increasing the spacing provides even greater advanced warning distance On the other hand, the spacings recommended for channelization devices are maximum distances If the devices are placed closer together, there's a more positive dominant path delineation There will be times when it's not possible to meet the suggested guidelines When that happens, we have to take other actions to compensate for shortcomings For example, we may not have enough room just to outline a lane change at the recommended distance We may compensate by using barrels in place of cones to outline the transition area Giving the driver a better view of what's expected When we speak of a traffic control zone, we're talking about the distance from the first advanced warning sign Until the point beyond the work area where traffic is no longer affected The sketch shown here and in the appendix B illustrates the five parts of a traffic control zone The first area that the driver sees is the advanced warning area Where we tell drivers what to expect ahead And then the second area that the driver encounters is the transition area Which is used to move drivers from one lane to another In the third area, the buffer space provides protection for traffic and for workers Next comes the work area The site of the work activity while the fifth and final area Is the termination area where traffic resumes its normal patterns And assumes the normal use of lanes We'll take a look at each of these zones in some detail The first area, the advanced warning area, lets drivers know what to expect before reaching the work area The advanced warning area may vary from a series of signs starting a mile in advance of the work area To a single sign or flashing lights on a vehicle On high speed roadways, three advanced warning signs are typically used The first sign tells the driver to pay attention You're approaching a work site And the second sign tells the driver the situation ahead is as follows And the third sign tells the driver what action is to be taken Let's consider a simple two lane roadway closure Where we are going to reduce to one lane to be shared by both directions of travel Our first sign will say road work ahead The second sign states that there is a one lane road ahead While the third sign gives specific instructions In this case, a flagger symbol The distance we use between these signs is 500 feet Or let's take a maintenance project on a multi lane highway Here we're going to close the outside lane so all traffic will be shifted over to the left lane The first sign, road work ahead warns the driver that something unusual is happening on the roadway The second sign, right lane closed, specifically tells the driver what is happening And the third sign gives specific instructions to the driver A merge left where the arrow indicates the direction Or the pavement narrow symbol may be used also With these three signs, we didn't show any particular distances On the sign, but simply the word ahead Because in most maintenance projects, it's not possible to give specific dimensions When we have freeways, we may want to have a longer warning area As great as one mile in advance of the work site We can do that by increasing the spacing And since we are increasing the spacing and since we are increasing the distance The driver may become inattentive So we may want to put up more signs in the warning series A typical sequence might be First sign, road work ahead Second sign, right lane closed The third sign, a merge left with the arrow And finally, a fourth sign with the pavement with transition symbol Okay, let's move on to the second area This is the transition area And in the transition area, we have the tapers that are used to close lanes Where the taper is a series of channelizing devices Placed on an angle to move traffic out of its normal path There are three general types of tapers used in traffic control zones The first type are lane closures or channelizing tapers And these are used to close lanes to moving traffic The second are the two-way traffic tapers And they're used to control two-way traffic Where traffic from each direction is required to share a single lane And finally, the third type of taper is the shoulder closure taper And these are needed to close shoulder areas Let's take a look at each of these three tapers in more detail The length of a lane closure taper is determined by the speed of traffic And the width of the lane to be closed The formulae for the length of tapers are shown here For speeds of 35 miles an hour or less, the length of taper is the width of lane Multiplied by the square of the velocity and divided by the number 60 For example, if we're going to move over one 12-foot lane At a speed of 35 miles an hour, the minimum length of taper Is 12 multiplied by 35 squared divided by 60 Which works out to be a length of 245 feet In appendix B, you'll see it shows a minimum length of 250 feet For all speeds less than 35 miles an hour Which distance, of course, is slightly greater than the minimum Given by the formula at 35 miles an hour For speeds in excess of 35 miles an hour, the minimum length of taper Is equal to the width of transition multiplied by the speed in miles per hour If we're going to move over a 12-foot lane at 55 miles an hour Our taper length would simply be 12 times 55 Or a 660-foot taper Again, appendix B shows a minimum length of 750 feet for velocities of 50 or 55 miles an hour Greater than the minimum value calculated from the formula Now, if sight distance is restricted, the taper should begin well in advance of the view obstruction Tapers can be outlined with 12 to 16 channelizing devices Such as cones or type 1 barricades But if you use type 3 barricades in conjunction with a flashing arrow board 3 or 4 devices can be used to outline the taper Now, in the case of the second type of taper, the two-way tapers We don't want drivers to have that smooth transition into the adjacent lane We want a much shorter transition area so that drivers are aware of the need to slow down Or stop as directed by the flagger Two-way traffic tapers are only 50 feet long Substantially less than tapers used for a smooth transition from one lane to another Five channelizing devices are sufficient to outline the taper Although, again, if we're using type 3 barricades Two of those will provide satisfactory guidance The last type of taper, a shoulder closure taper, is used on high-speed roadways Where drivers expect to use the improved shoulder in emergencies Since drivers using the shoulder in these circumstances are traveling at a slower pace We use a taper which is about one-fourth the length of a lane closure taper For example, on a roadway with a 55-mile-an-hour speed limit, the lane closure would be at least 750 feet in length and outlined with 16 cones as we just developed But the shoulder closure taper would be only about 200 feet long, outlined with 8 or 9 cones The third part of a traffic control zone that the driver will see is the buffer space between the transition area and the work area In a mobile operation, this would be the space between the shadow vehicle and the work vehicle As we already mentioned, if a driver fails to see the advanced warning or doesn't make the transition, this space allows a driver to stop before reaching the work area This is certainly no place to leave equipment, materials, or your own vehicle There are no specific guidelines on the length of a buffer space But a distance of 300 feet will allow a driver traveling at 55 miles-an-hour to come to a safe stop on wet pavement, even if the brakes are applied only at the start of the buffer space A 300-foot buffer space on a high-speed roadway Remember, we're talking about speeds of 40 miles-an-hour or more It should be the minimum distance that you consider But at slower speeds or on city streets, a buffer space of 50 to 200 feet should prove to be enough The fourth area includes not only the work activity, but also room for workers, equipment, and construction materials In establishing a work zone, it's important to provide a safe entrance and exit for work vehicles The work area may remain in a fixed location, or it may be moved as work progresses The work area and the buffer area appear as a continuous space to the driver The work area is delineated with channelizing devices, and the spacings of these devices is about 2 times the speed limit About 110 feet to 55 miles-an-hour, or 50 feet at 25 miles-an-hour Now the length of the work zone is going to have an effect A work zone 500 feet in length will require from 6 to 11 devices But a short work zone, only 100 feet long, would require only three devices at a 50-foot spacing, and that's an inadequate number In general, the shorter the workspace, the more devices we should use for every unit length Conflicting information calls for shorter spacing between devices If we're doing a temporary lane shift and don't take the time to erase old lane lines We want to put in more devices to increase the driver's concentration on the new shifted pathway And the final area, the termination area, provides a short distance for traffic to clear the work area and to return to the normal traffic lanes A downstream or closing taper may be used in this area These tapers, about 50 feet in length, give added assurance to drivers and help to remove any confusion about gaps in traffic control For example, if the work area includes intermittent activity over a one-mile segment The drivers should be reminded that they are still in a work area In this case, a termination area gives positive guidance to the driver about the end of the project We can examine a typical treatment for a slow-speed roadway The warning area begins 950 feet in advance of the actual work site The first sign is roadwork ahead 250 feet further on is the second warning sign Right lane closed At 500 feet, we may place the optional third warning device A flashing arrow and begin the taper area The taper is 250 feet long, outlined with 11 cones at 25 foot spacing The buffer area is 200 feet in advance of the work area, which occupies another 100 feet The 300 foot buffer plus work area is outlined with cones at 50 foot spacing or a total of six cones beyond the end of the taper Finally, a 50 foot closing taper outlined with four or five cones will assure the driver that it's okay to return to the closed lane The total distance from the first warning sign to the end of the closing taper is 1100 feet All to control a work zone of 100 foot length In this second illustration, we will again assume a work length of 100 feet But the speed is 55 miles an hour The warning area consists of four signs rather than the two on the slow speed roadway The first warning sign that the driver sees is 4,050 feet in advance of the actual work area Signs are spaced at 750 feet They were at 250 feet The first sign has the same legend as for the slow speed Road work ahead The next two signs are the same as the second sign in the slow speed series Right lane closed The extra repetition gives the driver more time to anticipate and react to the lane closure The fourth sign in the series 2,250 feet from the first is a merge or pavement narrow symbol The taper begins 3,000 feet from the first warning sign And may be accompanied by a flashing arrow panel Now the second area, the transition area, is 750 feet in length Outlined with a minimum of 16 cones at a 50 foot longitudinal spacing The buffer area is at least 300 feet long And when added to the 100 foot work area gives us a total space 400 feet long that must be outlined At 55 miles an hour the suggested spacing would be 100 feet between cones There would only be four cones beyond the taper So that a spacing of about 70 feet using six cones would give us better delineation This illustrates the idea that standards are minimum It's often justifiable to provide more protection Finally the closing taper would again be about 50 feet Outlined by four or five cones the same dimensions we used on the slow speed roadway The total distance from the first warning sign to the last cone in the taper is 8 tenths of a mile Or 4,200 feet all required to protect a workspace of 100 feet Remember on the slow speed roadway the total length of the traffic control zone was 1100 feet To protect that same 100 foot workspace Although both of these zones have the same essential five elements of a traffic control zone The high speed zone is nearly four times the length of the slow speed zone Almost all of the difference reflecting the importance of speed and affirmative guidance to the driver Well this concludes our review of the principles of traffic control zone design and installation In the next session of this series We'll be applying these principles to some of the situations you'll be encountering in your work We've reviewed the need for traffic control at worksites Briefly discuss the devices that are available to us And we've examined some basic principles of the design of traffic control in work zones In this tape we'll consider some specific applications of traffic controls The details will be found in sections two and three of appendix b You may wish to refer to these sections as you follow the details of this tape Unfortunately, it's not possible to demonstrate or illustrate all of the possible applications That you will encounter in your work It's up to you to use your judgment and experience in making the correct decisions Remember in all circumstances the principal purpose of your traffic control Is to warn and guide the driver while he or she is approaching and passing through your work zone You're probably most vulnerable to hazard during the installation of the traffic control devices The way to minimize this hazard is to install the devices before work begins Starting with the first device the driver will see when approaching the area Then continue installing devices advancing toward the work area The best way to evaluate any work zone traffic control Is to drive through that work zone after all the devices are in place Difficult as it is put yourself in the place of the unfamiliar driver The one who is not anticipating your presence on the roadway If the traffic control scheme gives the driver the necessary warning and guidance You and your co-workers will be providing the best protection for yourselves while working on or near the roadway As soon as the work is completed the traffic control zone is removed in the reverse order of installation Starting with the termination area and proceeding back to the first device installed The best way to illustrate these principles is to detail the installation of the traffic control scheme for some common types of operations In our first example, we'll be working on a high speed two lane two-way highway The work being done makes it necessary to close one lane of the highway The traffic controls for this situation are found in layout 12 On page 3-2 of appendix B For this example, let's assume that the speed limit is 55 miles an hour And the highway is a major arterial route with relatively high traffic volumes This makes it necessary to use two flyers And to install the three advanced warning signs 750 feet apart The first sign installed is the roadwork ahead sign for the unobstructed roadway This sign is placed 2,550 feet beyond the work zone The second sign, one lane road ahead, is placed 750 feet from the first sign From the first sign The last sign installed The flagger symbol Is placed 750 feet from the second sign The first flagger then assumes his or her station 750 feet from the flagger sign The same series of signs are then installed on the side of the roadway on which the work is being done again Starting with a roadwork ahead sign 2,600 feet from the work area A one lane road sign at 750 feet A flagger symbol at another 750 feet And finally the flagger 750 feet beyond the last sign At this time the two flaggers begin controlling traffic through the one lane section Next we install the second traffic control element A 50 foot taper Made up of five channelizing devices The third element A 300 foot buffer space And the fourth element The work area are then outlined with channelizing devices Spaced at approximately 100 foot intervals A type 3 barricade or work vehicle is then moved into the closed lane At the end of the buffer space The final element installed is the 50 foot downstream taper at the end of the work area Now you may begin your work activity After the project is completed and all workers materials and equipment are off the roadway The traffic control devices are removed in reverse order of installation For the second example we'll be working on a low speed undivided four lane highway The work being done makes it necessary to close the left lane of the roadway The traffic controls for this situation are found in layout 5 of page 2-6 of appendix b For low speed applications Notice that the taper length and sign spacing is the same for all speeds from 0 to 35 miles an hour The first sign installed for the unobstructed roadway is a roadwork ahead sign This sign is placed 250 feet beyond the work zone The signs for the affected roadway are then installed The roadwork ahead sign is placed 1,000 feet before the work area The next sign is a left lane closed sign 250 feet from the roadwork ahead sign Now that all of your advanced warning signs are in place Place your work vehicle or advanced warning aero-planel in the closed lane in front of where the taper begins This is done to give you the worker added protection while setting up the taper For this application the lane closure taper Consists of 11 channelizing devices on 25 foot centers for a 250 foot taper Once the taper has been installed Move the advanced warning aero panel behind the lane closure taper The advanced warning aero panel should be placed as near to the beginning of the taper as possible The third element A 150 to 200 foot buffer space And the fourth element the work area are then outlined on both sides With channelizing devices spaced at 50 foot intervals The fifth element to be installed is a 50 foot downstream taper Finally the work vehicle may be moved into the closed lane near the work zone One quick note concerning advanced warning aero panels In the last example the advanced warning aero panel was placed in the lane because of the lack of a shoulder However as a rule Advanced warning aero panels should be placed on the shoulder at the beginning of the taper again The best way to evaluate work zone traffic controls is to drive through the work zone after all the devices are in place remember Put yourself in the place of the unfamiliar driver the one who's not anticipating your presence on the roadway And now you're ready to begin your work activity After the project is completed and all workers and materials and equipment are off the roadway The traffic control devices are again removed in reverse order of installation For our third example, we'll be working on a high speed divided multi-lane highway The work being done necessitates that the left lane be closed The traffic controls for this situation are shown in layout 18 on page 3-8 of appendix b again We'll assume that the posted speed limit is 55 miles an hour The first element installed is the advanced warning area Which begins 3,300 feet before the work area For one-way multi-lane roadways The advanced signs are generally installed on both the left and right sides of the roadway The first two signs installed are the two roadwork ahead signs 3,300 feet before the work area on both sides of the roadway next Two left lane closed signs are placed 750 feet from the first signs again One on each side of the roadway The third set of signs consists of a merge sign with an arrow and a lane reduction transition sign In our example We placed the merge sign with an arrow on the left side of the roadway And the lane reduction transition sign on the right side of the roadway These signs are placed 750 feet from the left lane closed signs Next we install the second element of traffic control the lane closure taper again When setting up the taper Place your work vehicle or an advanced warning arrow panel before the start of the taper for added protection For this example The lane closure taper consists of 16 channelizing devices on 50 foot centers for a total of 750 feet The lane is closed by a type 3 barricade Which you place at the end of the taper Now the optional advanced warning arrow panel If used can be placed on the shoulder at the beginning of the taper The third element A 300 foot buffer space and the fourth element The work area are outlined by channelizing devices spaced 100 feet apart Finally The work vehicle may be moved into the closed lane near the work area and the fifth element A 50 foot closing taper is installed After the project is completed and you remove yourselves and all of the equipment and materials The traffic control devices are removed in reverse order of installation The final examples we'll examine in this tape Are those of mobile operations Appendix B defines a mobile operation as Any operation where the traffic control zone remains in one place for less than 15 minutes Mobile operations should be used only during daylight hours And at locations that offer good visibility When the site distance approaching any mobile operation is restricted A flagger should be used to protect the work area and to warn the driver The first mobile operation we'll examine is on a high speed two-lane two-way highway The work being done makes it necessary to close one lane This situation is shown in layout 13 on page 3-3 of appendix B This situation shows two vehicles used to provide traffic control However, more can be used for additional protection The shadow vehicle should be on the shoulder 750 to 1500 feet before the work vehicle Where the shoulder is narrow the vehicle can be partially in the lane The shadow vehicle shall be equipped with a 360 degree flashing beacon And the proper advance warning signs A type B or type C advanced warning arrow panel is optional in this case If an advanced warning arrow panel is used The flashing caution symbol as illustrated in layout 13 should be used Never use a flashing arrow which would direct cars into the path of oncoming traffic The work vehicle shall be placed in the lane This vehicle shall be equipped with a 360 degree flashing beacon However, no warning signs are needed The second mobile operation is an operation on a roadway Where the conditions are the same as the previous example But in this situation the roadway carries a low volume of traffic Appendix B defines a low volume roadway as any street or highway Where the average daily traffic is less than 1,500 vehicles per day This example can be found in layout 14 on page 3-4 of appendix B In this situation no shadow vehicle is needed The work vehicle shall be equipped with a 360 degree flashing beacon But no additional signs are required The final mobile operation that we'll consider is a high speed divided multi-lane roadway This example is illustrated in layout 23 on page 3-13 of appendix B Under these conditions a shadow vehicle is used It should be on the shoulder and approximately 1,000 to 1,500 feet before the work vehicle The shadow vehicle shall be equipped with a 360 degree flashing beacon A Type-B or Type-C advanced warning arrow board and the proper advanced signs The work vehicle shall be located in the closed lane And shall display a 360 degree flashing beacon And a W1-6 warning arrow or a Type-B or Type-C flashing arrow board These are the three basic setups for mobile operations Remember, these operations are only for daytime hours and only in locations which offer good visibility We've briefly reviewed a few examples of layouts under a number of different conditions But this small number cannot nearly begin to address all of the possible situations that you will encounter You will often be called upon to develop your own traffic control plan Providing safety for both workers and drivers While this task may be time consuming It is part of your responsibility that can never be set aside because of anxiety to get on with the job I hope this series of tapes has been of value to you And I wish you well as you continue with your important responsibilities Your safety, the safety of your fellow workers and the safety of the driving public Depends on whether you execute your flagging duties properly You may be assigned as a flagger for an entire shift Or for a short period of time to relieve a fatigued fellow worker You are in contact with the public and your attitude directly affects the public's perception of operations The Minnesota Department of Transportation has developed a flagging handbook To help you fully understand your flagging responsibilities This flagging handbook can be found in the Appendix B of the Minnesota Manual on Uniform Traffic Control Devices This tape was developed as an additional aid in preparing you to be flaggers If you ever have any questions on flagging operations Never hesitate to ask your supervisor Because as stated before, a flagger's responsibilities are of primary importance in maintaining safety in the work zone Cindy and Joe, Highway Maintenance Workers for the Minnesota Department of Transportation Will demonstrate most of the procedures and techniques used when assigned flagging responsibilities Your first responsibility as a flagger is to ensure that you have the proper clothing and equipment and that it is in good condition Improper equipment reduces the driver's ability to interpret your instructions Neat dress and appearance also help you gain the driver's respect which makes your job that much easier Your clothes should consist of a shirt, pants, shoes, an orange vest, shirt, or jacket with an orange or yellow hat Safety rules and regulations on flagging vary from one road authority to another And your supervisor will inform you on any specific requirements for your area The primary traffic control device used by flaggers is the stop slow paddle sign The standard paddle sign shall be at least an 18 inch by 18 inch octagon Attached to a minimum five foot staff As with other traffic control devices, this sign shall be reflectorized Because drivers are sometimes unalert, fatigued, or preoccupied Your second duty as a flagger is to remain alert at all times and stay on your feet facing oncoming traffic Always stand alone in a highly visible location away from other workers and work vehicles Never stand directly in the path of an approaching vehicle Your next responsibility as a flagger is to use your equipment properly Generally, flagging operations require three basic skills stopping releasing and slowing traffic To stop traffic Stand on the shoulder of the roadway with the stop sign erect and away from your body Look directly at the approaching traffic and raise your free hand with the palm exposed to the approaching driver After you have stopped the first vehicle Walk out to the center of the roadway so additional approaching traffic can see the stop paddle Remember never stand in the path of oncoming traffic After traffic is stopped, there are two ways to release traffic The first way is to release traffic into the left lane And the second way is to release traffic into the right lane To release traffic into the left lane, remain standing to the front and to your right of stopped traffic Turn the slow side of the sign to face the vehicles And with your free arm, signal the drivers to proceed into the left lane Never wave the sign After all the vehicles have passed, return to your original position on the shoulder to await the next vehicle The second way to release traffic is into the right lane After you have stopped traffic and are standing near the center line Return to your position on the shoulder Display the slow sign to the drivers and with your free arm, motion the drivers to proceed In some cases, it may not be necessary to completely stop traffic, but only to slow it down In these cases, always stand on the shoulder of the road Displaying the slow paddle to oncoming traffic Use your free arm to avoid the traffic And use your free arm to motion traffic to slow down Remember, never stand in the path of oncoming traffic These three basic skills are the only actions you need to know for a successful flagging operation Situations will vary and how you apply these skills will differ from project to project We will cover some typical situations you as a flagger may find yourself in Before starting any of these flagging operations, an issue must be addressed In most flagging operations, advanced warning signs as shown in the flagging handbook Should be set up before the flagger actually starts controlling traffic These signs tell the driver that you are controlling traffic up ahead Without these advanced warning signs, the driver does not expect your presence on the roadway Once the advanced warning signs are in place, you may begin flagging The first situation that requires a flagging operation is that of an advanced flagger The advanced flagger is placed well ahead of the work zone As an advanced flagger, you should stop each vehicle and advise the driver of the situation ahead And any appropriate action required Always be alert, considerate, and avoid any unnecessary conversation The second situation we will cover is a single flagger operation The Minnesota Department of Transportation has developed a new system of flagging on low-volume highways that have less than 1,500 vehicles a day While flagging alone, stand on the shoulder of the closed lane facing oncoming traffic Remember, do not stand close to the work vehicles next to fellow workers or in the path of approaching vehicles Once the first car is stopped, you walk from the shoulder out to near the center line where you can see the opposing traffic In this single flagger operation, the opposing traffic continues uninterrupted When the way is clear, release traffic into the traveled lane The third situation, probably the most common, is that of a two-flagger operation In these cases, one flagger is always in charge to coordinate the operation When two flaggers are used, they must always be able to communicate with one another This can be done with two-way radios, flag carrying, or sight method For both flaggers must have visual contact The first flagger, Cindy, releases traffic and displays the slow paddle sign while the second flagger, Joe, stops traffic Traffic is held by Joe until an all-clear is received from Cindy, which allows him to release stopped traffic In this example, the flag carrying method of communication is used Cindy hands a flag to the last car she allows to go through When that driver reaches Joe, he hands him the flag Having gotten the all-clear, Joe can now allow traffic to flow safely in the opposite direction This operation is very simple However, communication between flaggers is imperative The flagger must be assured that the driver of the last vehicle will pass the flag to the other flagger The fourth situation considered in this presentation is that of nighttime flagging operations Nighttime flagging procedures are generally the same as daytime Except that some equipment changes are necessary A flashlight or lantern, a reflectorized vest, and a reflectorized stop slow paddle are required for nighttime flagging operations It is also helpful if auxiliary lighting can be added to illuminate the flagging station The more visible you are, the easier it is for the driver to see you and to follow your instructions To stop an approaching vehicle, stand on the shoulder holding the stop paddle away from your body Do not stand in the traveled lane Wave your flashlight or lantern back and forth in front of your body While holding the sign paddle in the usual manner To release traffic, use basically the same procedures that you use during daylight hours Do not wave the flashlight This might confuse the drivers The fifth situation involves only one flagger restricting only one direction of traffic An example of this is an area where trucks are loading and unloading and are partially blocking the lane The flagger stops traffic in the usual manner Once the work has been completed and the way is clear, the flagger releases traffic When releasing traffic on a two-lane highway where traffic is stopped temporarily in only one lane such as for loading and unloading operations The sign standard should be turned a quarter turn So that the letters stop face you as the flagger In this position, the sign should be parallel to the shoulder of the road So that neither stop nor slow can be read by motorists approaching from either direction The stop message will not confuse continuous traffic traveling the opposite direction The sixth and final situation deals with emergency situations In an emergency situation such as an accident or bridge out You will not always have the proper equipment readily available However, in situations like these, the public must be warned Flaggers in emergency situations, but only in emergency situations May use an 18 inch by 18 inch red flag for flagging operations As soon as the proper equipment is available, the flags should not be used Remember, no matter what flagging procedure you are using Always stay alert Face oncoming traffic Stand alone in a good visible location Away from any work vehicle and never stand in the path of approaching vehicles Everyone, including the motorist Your fellow workers And you yourself are dependent on your ability to properly follow these flagging procedures