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BACKGROUND OF THE INVENTION 
     The use of highway signs to warn “wrong way” drivers driving in one or more adjacent lanes wherein vehicles are moving in opposite directions is well known, so as to reduce the incident of serious and often fatal accidents. In order to achieve this objective, such signs have been positioned in a variety of different ways, with more or less success. In some cases, the drivers fail to see the signs as positioned, and in some cases the signs are positioned so as to be clearly seen by drivers going in the correct direction, startling them and causing them to panic and react inappropriately, sometimes in a dangerous manner. In the case of roads wherein there are multiple lanes moving in the same direction, for example, such signs positioned on the outside shoulders of the outer lanes are not seen by drivers going the wrong way in the inside lanes. This problem is aggravated by the tendency of drivers to look rightward to view signs, and to disregard signs to their left, which is where the “wrong way” signs would be positioned as they proceeded in the wrong direction. In order to remedy this problem, in some cases “wrong way” signs have been positioned in the roadway median between opposite moving lanes. This has led to the problem referred to above, namely that drivers going in the correct direction also clearly view such signs, and are startled, especially drivers new to that particular sign usage area. Also, drivers who see such “wrong way” signs often soon come to ignore them, so will likely continue to ignore them when they are, in fact, going in the wrong direction. There is thus a need in the art for sign assemblies which will remedy these problems, and also reduce the number of signs needed, and according the cost of placing such signs. This is true both in the case of multilane roads, and in the case of roads with only a single lane in each direction. 
     SUMMARY OF THE INVENTION 
     The present invention relates to sign assemblies primarily designed to be positioned at an inclined angle in or above roadway medians or between railroad tracks and having view obstructing means thereon, or adjacent to their lateral edges, which permit drivers going the wrong way on roads or in trains to clearly see such warning indicia as ‘WRONG WAY’, but which at least partially obstruct the view of such indicia by drivers going the correct way, so as not to confuse them. It also relates to methods of positioning such assemblies between such roads or railroad tracks. It has utility in the medians of multilane roads, in the medians of two lane roads and mounted on bridges or overpasses. It could also be used between walking paths or industrial paths, for example. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a plan view of a multilane roadway having a preferred embodiment of the invention installed in the median, wherein such indicia as “WRONG WAY” is used on both sides of the signs. 
         FIG. 2  is a plan view of one existing prior art arrangement of “WRONG WAY” signs on a multilane road. 
         FIG. 3  is a plan view of a modified type of sign assembly wherein such indicia as “WRONG WAY” is used on only one side of each sign, on opposite sides of the two signs shown. 
         FIG. 4  is an elevation view of the type of sign used in  FIG. 3 . 
         FIG. 5  is a plan view of the type of sign used in  FIG. 3 . 
         FIG. 6  is an elevation view of the type of sign shown in  FIG. 1 . 
         FIG. 7  is a plan view of the type of sign used in  FIG. 1 . 
         FIG. 8  is an elevation of the type of sign used in  FIG. 1 , with a modified mounting means comprising a pole, and utilizing a top support bar. 
         FIG. 9  is a plan view of the sign of  FIG. 8 . 
         FIG. 10  is an elevation of the type of sign used in  FIG. 1 , but utilizing modified mounting means comprising dual support elements. 
         FIG. 11  is a plan view of a prior art “wrong way” sign arrangement used on a two lane road. 
         FIG. 12  is a plan view of an arrangement wherein the  FIG. 1  type of sign is used in the median of a two lane road. 
         FIG. 13  is an elevation of a sign assembly mounted on the vertical face of a bridge or overpass. 
         FIG. 14  is a plan view of the sign assembly shown in  FIG. 13 . 
         FIG. 15  is a plan view of a sign having ends of the projecting means bent backwards to form smooth edges. 
         FIG. 16  is a plan view of our invention positioned between railroad tracks. 
     
    
    
     DETAILED DESCRIPTION 
     Illustrated in  FIG. 1  is a plan view of a portion of a four lane road having a median  3 , two north-bound lanes  20 , two south-bound lanes  21 , and an embodiment of the present invention mounted in the median comprising two ‘WRONG WAY’ signs  1 , which may be of the same or similar construction, more particularly as shown in  FIGS. 6-10 , for example. These signs may display such indicia as “WRONG WAY” on both faces, and may be mounted by any of various mounting means  14 ,  15  or  18  as shown in various of  FIGS. 6-10 , for example. As also shown in all of these figures, the signs have partial view obstructing means  2  projecting from their vertical edges, or adjacent such edges, and have faces which are inclined relative to the direction of travel of the vehicles in lanes  20  and  21 . Partial view obstructing means  2  would of course at least partially obstruct view of the indicia from positions generally forward of and lateral relative to the faces of the signs. The correct direction of travel in all of the lanes is indicated by solid arrows  4 , and an incorrect direction of travel is indicated by dashed arrows  5 . 
     It will be seen that the view of the indicia by drivers going the correct direction in all of the lanes will be partially obstructed by view obstruction means  2 , especially as they approach and pass the signs. However, the view of the indicia by any drivers going the incorrect way in any of the lanes will be unobstructed, so that they will have a clear view of indicia, such as “WRONG WAY.” Consequently, drivers going in correct directions will immediately recognize that the signs are not applicable to them, and drivers going in incorrect directions will immediately recognize their error. Drivers going the wrong way will, in fact, observe indicia such as “WRONG WAY” at an optimum angle of 90 degrees. 
     It may be noted that signs  1  will be located to the right of any drivers going in incorrect directions  5 , which is especially desirable, because drivers are accustomed to looking to their right for controlling signs. Lanes  20  and  21  are labeled as running in north-south directions merely to facilitate understanding of the invention. Of course, the invention would be equally useful when used between lanes running in any two opposite directions, such as east-west. 
     Such variables as the most useful angle of inclination of the signs relative to the direction of travel of the vehicles, the size of the signs, the height of their mounting, the height or angle of obstructing means  2  on their edges, or the size and wording of the indicia, are subject to variation, based on experience. The most useful angles of inclination between the direction of travel and the faces of the signs may be in the range of substantially 120 to 135 degrees. The most useful angle of the obstructing means  2  relative to the faces of the signs may be in the range of 90 degrees. But those angles are obviously subject to variation depending on experience or particular usage. View obstructing means  2  would at least partially obstruct view of the indicia from positions located generally forward of and lateral relative to the face of the sign by drivers going the correct way, as noted above. Such positions could, for example, be in the range of substantially 140 to 160 degrees relative to the face or faces of the sign. 
     It is presently believed that the most useful height at which to mount the signs would be at a moderate height relative to ground or grade level, such as approximately at or a little above the average eye-level height of vehicle drivers passing the signs. 
     The indicia could be made from a reflective material, so as to be more clearly visible at night, or could be illuminated by solar-powered means. 
       FIG. 2  shows a portion of a prior art four lane road comparable to the four lane road of  FIG. 1 . As is the case in  FIG. 1 , there are two northbound lanes  20  and two southbound lanes  21 . Mounted at  18  is a sign with “WRONG WAY” displayed on only the south-facing face, and intended to warn drivers going in the wrong direction in either of lanes  21  of their error. Mounted at  19  is a sign with ‘WRONG WAY’ displayed on only the north-facing face, and intended to warn drivers going the wrong way in either of lanes  20  of their error. Mounted in median  3  at  6  is a sign having “WRONG WAY” displayed on both faces, and intended to warn drivers going in the wrong direction in any of lanes  20  or  21  of their error. It will be seen that the faces of all of signs  6 ,  18  or  19  are positioned at 90 degrees relative to the direction of vehicle travel. Sign  6  is seen to be needed, in addition to signs  18  and  19 , because drivers going the wrong way might not see either of signs  18  or  19 , especially because these signs would be located to the left of such wrong-way drivers, where they would not expect to see signs controlling their movement. However, use of this sign arrangement causes drivers going in the correct direction in any of lanes  20  and  21  to get a full and very confusing view of the ‘WRONG WAY’ indicia on sign  6 . This might well startle drivers going in a correct direction, and cause them to panic and react in a dangerous manner. In addition, drivers frequently passing this prior art sign arrangement soon become accustomed to seeing ‘WRONG WAY’ signs, such as sign  6 , in full and close view, and consequently could be expected to just continue to ignore such signs if they were, in fact, going in the wrong direction. 
     The  FIG. 1  embodiment of our invention eliminates all of these problems caused by confusing sign  6 , and results in an arrangement by which wrong-way drivers are more likely to realize and correct their error. Although two signs  1  are shown close together in  FIG. 1  for purposes of illustration, only one such sign would be needed on a particular extended portion of a road, or roads. In other words, signs  1  could be spaced far apart on roads. One might be placed near to where any access roads presented locations where drivers could enter in the wrong direction. Signs such as signs  18  and  19  could continue to be used, of course, or could be eliminated as unnecessary to reduce expense, all of signs  6 ,  18  and  19  being replaced by a single sign  1 . 
       FIG. 3  shows another embodiment of our invention wherein signs  7  and  8  are used to warn drivers going the wrong way. In this embodiment, sign  8  has ‘WRONG WAY’ displayed on only its north (or, more precisely, northeast) facing face, to warn drivers going the wrong way in lane  20  of their error, and sign  7  has “WRONG WAY” displayed on only its south (or, more precisely, southwest) facing face, to warn drivers going the wrong way in lane  21  of their error. It will be apparent that this embodiment of our invention differs from our  FIG. 1  embodiment in that signs  7  and  8 , unlike sign  1  as used in  FIG. 1 , have ‘WRONG WAY’ displayed on only one face, and have view obstructing means  2  projecting from only one such face. Drivers going the correct way in lane  20  would not be able to see “WRONG WAY” on the north face of sign  8 , since it would appear on only the side of sign  8  that faced away from them as they approached sign  8 . Likewise, drivers going the correct way in lane  21  would not be able to see “WRONG WAY” on the south face of sign  7 , since it would appear on only the side of sign  7  that faced away from them as they approached sign  7 . Drivers going the correct way in lane  20  would have their view of “WRONG WAY” on the south face of sign  7  partially obstructed by view obstructing means  2  on sign  7 . Drivers going the correct way in lane  21  would have their view of “WRONG WAY” on the north face of sign  8  partially obstructed by view obstructing means  2  on sign  8 . It may be seen that signs  7  and  8  do, in fact, have exactly the same construction, although they are mounted in rotated positions relative to each other. Because they would be so rotated relative to each other when mounted, they have been given different reference numerals, even though they would be of the same construction. Signs  7  and  8  could be mounted relatively close together, as shown in  FIG. 3 , or spaced far apart. They could also be used to control multi-lane roads, as shown in  FIGS. 1 and 2 , as well as to control two lane roads, as shown in  FIG. 3 . Additional signs such as signs  18  and  19  could continue to be used, or they could be omitted, as desired. 
       FIGS. 4 and 5  show elevation and plan views, respectively, of a sign  7  that is secured to a mounting channel  9  by bolts  10 . Channel  9  would extend up from the ground or road grade and hold sign  7  at a moderate elevation, which could be at eye level or, for example, somewhat above eye level. 
       FIGS. 6 and 7  show elevation and plan views, respectively, of a sign  1  as shown in the  FIG. 1  embodiment, being mounted by bolts  13  to a cross piece  14 , which in turn is mounted to a support  11  by bolt  12 . 
       FIGS. 8 and 9  show elevation and plan views, respectively, of a sign as shown in the  FIG. 1  embodiment, having alternate mounting means comprising a slotted cylindrical post  15 , and having an optional strengthening bar  17  secured to the top of the sign, to make it more wind resistant and stronger. Strengthening plates could be used in lieu of bar  17 , of course, as well as at the bottom of sign  1 . 
       FIG. 10  shows an elevation view of the  FIG. 1  type of sign, wherein it is mounted by bolts  19  to two channel or post members  18 . 
       FIG. 11  is a plan view of a prior art arrangement similar to the prior art arrangement of  FIG. 2 , except with signs intended to control two lanes, instead of four lanes. Signs  22 ,  23  and  24  would be constructed in the same manner as signs  6 ,  19  and  18 , respectively. And since sign  22  would have ‘WRONG WAY’ on both sides, as does sign  6 , it would also cause the same problems. 
       FIG. 12  is a plan view using a sign as shown in our  FIG. 1  embodiment, having “WRONG WAY” on both faces, mounted in median  3 , for warning drivers going in the wrong direction in either of lanes  20  or  21 . This would be an improvement on the prior art arrangement of  FIG. 11  in that all of signs  22 ,  23  and  24  could be omitted, eliminating the confusion caused by sign  22 , and reducing costs, since three signs could be replaced by a single sign  1 . In addition, it will be seen that even if sign  22  was omitted in the  FIG. 11  prior art arrangement—that is, if only signs  23  and  24  were used—these two signs could be replaced by a single sign  1 . In fact, sign  1  would be more likely to be seen because it would be to the right of drivers going the wrong way, unlike signs  23  and  24 . 
       FIGS. 13 and 14  are elevation and plan views, respectively, of a ‘WRONG WAY’ sign  28  mounted on an overhead bridge or overpass  25  by means of a mounting element  26  secured to the bridge or overpass  25  and to sign  28  by bolts  27 . Sign  28  would be inclined to the direction of vehicle travel on the road or roads below, as in our previous embodiments, and might also be inclined in a downward direction in order to facilitate its viewing by a driver on the road below, as shown. As in the previous embodiments, view obstructing means  2  would at least partially obstruct the view of “WRONG WAY” by a driver going the correct way in a lane to the right side of sign  28 , but would permit a clear view of same by a driver going the wrong way in a lane below or to the left of sign  28 . Of course, many different types of mounting means could be used in lieu of mounting means  26  and  27 . 
       FIG. 15  is a plan view of our  FIG. 1  type of sign constructed of a relatively thin sheet of material  31  bent back upon itself at the outer edges of view obstructing means  2  to form a stronger and perhaps more visually appealing sign. Of course, this could also be done in the embodiment of  FIGS. 4 and 5 . 
       FIG. 16  is a view of our invention wherein a sign  1  as described above is positioned between northbound railroad tracks  33  and southbound tracks  34 . 
     Although various embodiments of our invention have been described by way of example, it will be apparent to those skilled in the field that modifications may be made to such embodiments without departing from the scope of the invention.

Summary:
Highway or railroad sign assemblies having partial view obstructing means on their edges, mounted at an inclined position between or above road lanes or railroad tracks wherein vehicles or trains are traveling in opposite directions, and adapted to warn drivers that are going in the wrong direction without confusing drivers going the right way, and methods for so positioning such sign assemblies.