A system includes a glare-blocking member including a left recess, a right recess, and a rail including, a left lateral portion including a left protrusion configured to mate with the left recess of the glare-blocking member, a right lateral portion including a right protrusion configured to mate with the right recess of the glare-blocking member, and a projecting contour disposed between the left and right lateral portions, wherein an apex of the projecting contour is disposed farther from a line passing through lower edge portions of the rail than is either the left or the right protrusion.

RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 14/180,175, filed Feb. 13, 2014, which claims priority to U.S. Provisional Application No. 61/765,168, filed Feb. 15, 2013, the contents of which are both hereby incorporated by reference in their entirety. 
    
    
     TECHNICAL FIELD 
     This application relates to a glare screen for a concrete barrier wall. In particular, this application relates to a modular glare screen for a barrier wall. 
     BACKGROUND 
     Concrete barriers are typically utilized to divide opposite flowing lanes of traffic. To prevent head light glare, glare screens may be attached to the top of the concrete barriers. The glare screens may utilize a number of blades connected to one or more rails. 
     Existing glare screens require complicated assembly of the blades to the rails. For example, brackets, nuts, rivets, bolts, pins, etc. may be required to secure the blades to the concrete barriers. Such requirements make it time consuming and relatively difficult to assemble and disassemble the glare screen. 
     Preassembly of the glare screens (or portions thereof) may be performed at a remote location. The preassembled glare screens may be transported to the work site for installation. However, assembled glare screens may be bulky and hard to handle, and may require more truck space and trips to the work site. 
     Glare screens may also be assembled in the field. While more product may be delivered per load when glare screens are transported unassembled, assemblers may be required to assemble the glare screen in potentially dangerous construction zones and in unpleasant outdoor conditions. 
     SUMMARY 
     In a first aspect, a glare-blocking system includes a glare-blocking member and a rail. The glare-blocking member includes a bottom edge, a left recess, and a right recess. The rail includes a left lateral portion that includes a left protrusion configured to mate with the left recess of the glare-blocking member. The rail also includes a right lateral portion that includes a right protrusion configured to mate with the right recess of the glare-blocking member. The rail includes a projecting contour between the left and right lateral portions that defines a groove configured to receive the bottom edge of the glare-blocking member. 
     In a second aspect, a glare-blocking member for a barricade includes a top edge and a bottom edge. Left and right edges of the glare-blocking member extend between the top edge and the bottom edge. A left recess is formed in the left edge proximate to the bottom edge. A right recess is formed in the right edge proximate to the bottom edge. The glare-blocking member is configured to be inserted into a rail that runs along a top of the barricade. The left and right recesses are configured to receive a pair of protrusions at either end of the rail when the glare-blocking member is inserted into the rail. The recesses cooperate with the protrusions to secure the glare-blocking member to the rail. 
     In yet another aspect, a rail for a barricade includes a first vertical edge portion on a left side of the rail that defines a first protrusion at an end of the first vertical edge portion that is configured to mate with a first recess of a glare-blocking member. The rail includes a second vertical edge portion on a right side of the rail that defines a second protrusion at an end of the second vertical edge portion that is configured to mate with a second recess of the glare-blocking member. The rail includes a projecting contour between the first and the second vertical edge portions that defines a groove configured to receive a bottom edge of the glare-blocking member. 
     Other aspects, features, and advantages will be, or will become, apparent to one with skill in the art upon examination of the following figures and detailed description. It is intended that all such additional features and advantages included within this description be within the scope of the claims, and be protected by the following claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings are included to provide a further understanding of the claims, are incorporated in, and constitute a part of this specification. The detailed description and illustrated embodiments described serve to explain the principles defined by the claims. 
         FIG. 1  illustrates an exemplary glare-blocking system; 
         FIG. 2  illustrates grooves of the rail; 
         FIGS. 3A-3E  illustrate top views of exemplary rail embodiments; 
         FIG. 4  illustrates a cross-section of a rail and a side view of a portion of a glare-blocking member; 
         FIG. 5  illustrates exemplary operations for insertion of a glare-blocking member into a rail; and 
         FIG. 6  illustrates an exemplary tool that facilitates removal of a glare-blocking member from a rail. 
     
    
    
     DETAILED DESCRIPTION 
     The embodiments described below overcome the problems with existing glare screens by providing a rail with sections configured to deflect to allow for the quick insertion of a glare-blocking member into the rail. 
       FIG. 1  illustrates an exemplary glare-blocking system  100 . Shown are glare-blocking members  110  and a rail  105 . The rail  105  is fastened to a barricade  115 , such as a concrete traffic barrier, via a fastener  120 . The fastener  120  may be a self-tapping bolt or a different type of fastener. The rail  105  may have a length of about 12 feet or a different length. In an exemplary implementation, the glare-blocking members  110  are spaced along the rail  105  in a longitudinal direction at an interval of about 14½ inches. However, the spacing may be different. 
     As illustrated in  FIG. 2 , the rail  105  includes a set of grooves/cutouts  205   ab  across the width of the rail  105  for receiving a lower edge  210  of a glare-blocking member  110 . The gap width of each groove  205   ab  is sized to provide a snug fit with a glare-blocking member  110 . For example, the width may be about 0.188 inches. 
       FIGS. 3A and 3B , illustrate, respectively, a top view of a first rail embodiment  305 , and a top view of the first rail embodiment  305  with a glare-blocking member  110  inserted therein. In this embodiment, the grooves/cutouts  205   ab  are arranged to block headlight glare from oncoming traffic that is to the left of the driver. In one implementation, the grooves  205   ab  extend at an angle  307  of about 22 degrees with respect to a line that is perpendicular to a longitudinal axis of the rail  305 . 
       FIGS. 3C and 3D , illustrate, respectively, a top view of a second rail embodiment  310 , and a top view of the second rail embodiment  310  with a glare-blocking member  110  inserted therein. In this embodiment, the grooves/cutouts  205   ab  are arranged to block headlight glare from oncoming traffic that is to the right of the driver. 
       FIG. 3E , illustrates a top view of a third rail embodiment  315  that includes two sets of grooves/cutouts ( 320   ab  and  325   ab ) arranged to block headlight glare when the traffic flows in either situation described above. That is, the glare-blocking member  110  can be inserted into a first pair of grooves/cutouts  325   ab  to block headlight glare from oncoming traffic that is to the left of the driver, or into a second pair of grooves/cutouts  325   ab  to block headlight glare from oncoming traffic that is to the right of the driver. In this implementation, one set of grooves  320   ab  may extend at an angle  307  of about 22 degrees with respect to a line that is perpendicular to a longitudinal axis of the rail  305 . The other set of grooves  325   ab  may extend at an angle  307  of about −22 degrees with respect to a line that is perpendicular to a longitudinal axis of the rail  305 . 
       FIG. 4  illustrates a cross-section of the rail  105  and a side view of a portion of glare-blocking member  110 . The rail  105  includes a first set of left and right projecting contours  405   ab  that project in an upward direction toward the glare-blocking member  110  and a second set of left and right projecting contours  410   b  arranged adjacent to the first set of contours  405   ab , respectively, that project in an upward direction toward the glare-blocking member  110 . The rail  105  also includes left and right lateral side portions  415   ab  adjacent to the second set of contours  410   ab  that extend in a generally upright/vertical direction away from a line  412  that passes through lower edge portions of the rail  105 , and left and right side protrusions  420   ab  that extend from respective ends of the left and right lateral portions  415   ab . The left and right side protrusions  420   ab  slope in a downward direction towards the middle of the rail  105 . In an exemplary implementation, the protrusions  420   ab  slope downward at an angle  421  of about 22 degrees. However, the downward angle may be different. 
     The grooves  205   ab  may be formed in the first set of left and right projecting contours  405   ab . The grooves  205   ab  extend in a downward direction within the contours  410   ab  to a point that is below or at the apex of the second set of contours  410   b  when measured from the lower edge of the rail  105 . The second set of contours  410   ab  function as a stop to limit the insertion depth of the glare-blocking member  110  within the grooves  205   ab.    
     In some implementations, the rail member may not include the second set of contours  410   ab . In this case, the groove depth of the first projecting contours  405   ab , the location of the recesses  425   ab  in the glare-blocking member  110 , and the location of the protrusions  420   ab  may be selected to provide a tight fit between the glare-blocking member  110  and the rail  105 . 
     The glare-blocking member  110  is generally rectangular and includes first and second longitudinal edges  430   ab  and a lower edge  435 . In an exemplary implementation, the glare-blocking member  110  may be about 24 inches high and six inches wide. However, the dimensions may be different. As can be seen from a top view (see  FIG. 3B ), the glare-blocking member may define first and second end sections  307   ac , and a middle section  307   b  therebetween. The first and second end sections  307   ac  are configured to engage the rail  105  at angle of about 90 degrees with respect to the longitudinal axis of the rail  105 . The first and second end sections  307   ac  may be offset from one another so that that middle section  307   b  forms an angle of about 22 degrees with respect to the longitudinal axis of the rail  105 . 
     Returning to  FIG. 4 , first and second recesses  425   ab  are formed in the first and second longitudinal edges  430   ab , respectively, near the lower edge  435  of the glare-blocking member  110 . The lower edge  435  defines beveled corners  440   ab . The angle of the beveled corners  440   ab  may be selected to complement the downward angle of the protrusions  420   ab . In some implementations, the glare-blocking member  110  may include another pair of recesses (not shown) formed in the first and second longitudinal edges  430   ab , respectively, proximate a top edge (not shown) of the glare-blocking member  110 . The top edge may define beveled corners. The dual placement of these features facilitates reversing the orientation of the glare-blocking member  110  to facilitate insertion of the glare-blocking member  110  into the various rails illustrated in  FIGS. 3A-3E . 
       FIG. 5  illustrates exemplary operations for insertion of the glare-blocking member  110  into the rail  105 . The rail  105  may be initially fastened to a barrier  115  via a bolt  120  or a different fastener. In a first operation  500 , the glare-blocking member  110  is positioned so that the lower edge partially enters a first groove/cutout  205   b  and a recess  425   b  of a first edge of the glare-blocking member  110  is hooked into a first protrusion  420   b  of the rail  105 . In a second operation  505 , the glare-blocking member  110  is rotated about the hooked edge until the opposite edge contacts the second protrusion  420   a . As illustrated in a third operation  510 , continued application of rotational force on the glare-blocking member  110  causes the second protrusion  420   a  to deflect in an outward direction and the second protrusion  420   a  to ride over the beveled corners  440   a  of the glare-blocking member  110 . As illustrated in fourth operation  515 , the second protrusion  420   a  snaps into second recess  425   a.    
     In an alternative implementation, the glare-blocking member  110  may be positioned over the grooved section of the rail  105  and then pushed down towards the rail  105  until the lower edge  435  of the glare-blocking member  110  enters both grooves  205   ab  and the beveled corners  440   ab  of the glare-blocking member  110  engage the protrusions  420   ab  of the rail  105 . The force applied by continued downward pressure causes the protrusions  420   ab  to deflect in an outward direction and the protrusions  420  to ride over the beveled corners  440   ab  of the glare-blocking member  110  and to snap into the recesses  425   ab  of the glare-blocking member  110 . 
       FIG. 6  illustrates an exemplary tool  500  that facilitates removal of a glare-blocking member  110  from a rail  105 . The tool  500  includes a handle section  510 , an extension section  515 , and hook  520 . In operation, that tool  500  is positioned adjacent to a glare-blocking member  110  to be removed. The tool  500  is rotated so that hook  520  engages a first protrusion  420   b  of the rail  105 . After engagement, the tool  500  is rotated in an opposite direction until the extension section  515  reaches a lateral portion  415   ab  of the rail  105 . Continued rotation causes the protrusion  420   b  to deflect out of the recess  425   b  of the glare-blocking member  110 . Once the protrusion  420   b  is removed from the recess  425   b , the glare-blocking member  110  may be rotated out of the rail  105  with little effort. 
     While various embodiments of the embodiments have been described, it will be apparent to those of ordinary skill in the art that many more embodiments and implementations are possible that are within the scope of the claims. For example, the various dimensions, angles, etc. described above are merely exemplary and may be changed as necessary. Accordingly, it will be apparent to those of ordinary skill in the art that many more embodiments and implementations are possible that are within the scope of the claims. Therefore, the embodiments described are only provided to aid in understanding the claims and do not limit the scope of the claims.