Automatic barricade for low water crossings

Abstract

An automatic barricade includes a trench across a road that is covered by a grate allowing vehicular traffic during normal dry weather. Inside the trench is a series of barricade elements, each of which includes a float. When rising water fills the trench to a predetermined level, each float rises and elevates the elements above the road. The barricade elements are sufficiently robust and intimidating to deter motorists from driving over them but are spaced apart to be light enough to be easily actuated by the float. The barricade elements are sufficiently close together that vehicles cannot pass between them.

I claim:  
     
         1 . An automatic barricade in a road transverse to a normal traffic direction and intersecting a drainage path at a low water crossing, comprising a trench in the road extending transverse to the traffic direction, a cover spanning the trench and allowing vehicle traffic on the road during dry weather, a series of barricade elements in the trench and a system for raising the barricade elements from the trench into a position blocking vehicle traffic on the road in the normal traffic direction, the barricade elements being spaced apart in the traffic blocking position so the barricade is permeable to water.  
     
     
         2 . The automatic barricade of  claim 1  wherein the cover provides slots therethrough, the barricade elements being movable through the slots during movement to the position blocking vehicle traffic.  
     
     
         3 . The automatic barricade of  claim 2  wherein the cover is a grate having vertical passages adjacent the slots.  
     
     
         4 . The automatic barricade of  claim 1  wherein the trench is concrete lined.  
     
     
         5 . The automatic barricade of  claim 1  wherein the road rises away from the low water crossing through a series of increasing elevations, wherein the first mentioned automatic barricade is at a first elevation and further comprising a second automatic barricade at a second higher elevation in the road transverse to the normal traffic direction, comprising a second trench in the road, a second cover spanning the second trench and allowing vehicle traffic on the road during normal dry weather, a second series of barricade elements in the second trench and a second system for raising the second barricade elements from the second trench into a position blocking vehicle traffic on the road in the normal traffic direction.  
     
     
         6 . The automatic barricade of  claim 1  wherein the system for raising the barricade elements comprises a float in the trench at a location acted upon by rising water, the float and the barricade member being operably connected for elevating the barricade elements above the road when the rising water reaches a predetermined elevation.  
     
     
         7 . The automatic barricade of  claim 1  wherein the barricade elements are in the trench staggered in the direction of travel.  
     
     
         8 . The automatic barricade of  claim 7  wherein the barricade elements are in the trench staggered transverse to the direction of travel.  
     
     
         9 . The automatic barricade of  claim 1  wherein the barricade elements are in the trench staggered transverse to the direction of travel.  
     
     
         10 . The automatic barricade of  claim 1  wherein the low water crossing includes a drainage path providing a direction of water movement, the road having an upstream side and a downstream side, the trench having a closed end and an open end opening into the drainage path on the downstream side of the road.  
     
     
         11 . The automatic barricade of  claim 1  wherein the low water crossing includes a drainage path providing a direction of water movement, the barricade elements being mounted for arcuate movement from a stowed position in the trench toward an upright position blocking traffic, the direction of movement of the barricade elements between the stowed position and the upright position being the same as the direction of water movement.  
     
     
         12 . The automatic barricade of  claim 1  further comprising a latch for holding the barricade elements below the road and an operator for moving the latch in response to rising water over the road thereby allowing the barricade elements to move abruptly from a stowed position under the road to the traffic blocking position.  
     
     
         13 . The automatic barricade of  claim 1  further comprising a latch for holding the barricade elements in the traffic blocking position and an operator for moving the latch in response to subsiding water over the road thereby holding the barricade elements in the traffic blocking position and then allowing the barricade elements to move abruptly from the traffic blocking position to a stowed position below the road.  
     
     
         14 . The automatic barricade of  claim 1  wherein the drainage path crosses the road at a lowest spot in the road and wherein the trench is at a location above the lowest spot in the road.  
     
     
         15 . An automatic barricade assembly for placement in a trench in a road transverse to a normal traffic direction and adjacent a low water crossing, comprising a cover for spanning the trench, a series of barricade elements for placement in the trench and a system for raising the barricade elements from the trench into a position blocking vehicle traffic on the road in the normal traffic direction, the barricade elements being spaced apart in the traffic blocking position so the barricade is permeable to water.  
     
     
         16 . The automatic barricade assembly of  claim 15  wherein the cover provides slots therethrough, the barricade elements being movable through the slots during movement to the position blocking vehicle traffic.  
     
     
         17 . The automatic barricade assembly of  claim 15  wherein the barricade elements are staggered in the direction of travel.  
     
     
         18 . The automatic barricade assembly of  claim 16  wherein the barricade elements are staggered transverse to the direction of travel.  
     
     
         19 . The automatic barricade assembly of  claim 15  wherein the barricade elements are staggered transverse to the direction of travel.  
     
     
         20 . The automatic barricade assembly of  claim 15  further comprising a float operated latch for holding the barricade elements below the cover until a predetermined water level is reached.  
     
     
         21 . A method of controlling traffic along a road providing a direction of travel and providing a low water crossing across a drainage path, comprising 
 digging a trench in the road transverse to the direction of travel adjacent the low water crossing, the trench being open to rising water in the low water crossing;    placing a series of barricade elements in the trench for movement between a stowed position in the trench and an elevated position extending above the road;    placing a cover over the trench allowing vehicle traffic across the trench in dry weather;    in response to rising water in the trench, raising the barricade elements out of the trench to a series of spaced apart positions blocking traffic across the road and allowing water movement in the direction of travel.    
     
     
         22 . The method of  claim 21  wherein the road rises away from the low water through a series of increasing elevations, wherein the first mentioned automatic barricade is at a first elevation and further comprising 
 digging a second trench in the road transverse to the direction of travel at a second elevation higher than the first elevation at a second location spaced from the first mentioned automatic barricade;  
 placing a second series of barricade elements in the second trench for movement between a stowed position in the second trench and an elevated position extending above the road;  
 placing a second cover over the second trench allowing vehicle traffic across the second trench in dry weather;  
 in response to rising water in the second trench, raising the second barricade elements out of the second trench to a series of spaced apart second positions blocking-traffic across the road and allowing water movement in the direction of travel.  
 
     
     
         23 . The method of  claim 21  wherein the low water crossing includes a drainage path providing a direction of water movement, the road having an upstream side and a downstream side, and the digging step comprises digging an open end of the trench into the drainage path on the downstream side of the road and leaving an opposite end of the trench closed.  
     
     
         24 . The method of  claim 21  further comprising the step of flushing debris out of the trench including driving a water truck to a location adjacent the trench and discharging a volume of water from the truck into the trench and allowing the volume of water to run out of the trench into the drainage path.  
     
     
         25 . An automatic barricade in a road structure intersecting a drainage path at a low water crossing where flood water rises above a traffic surface of the road structure, comprising a series of barricade elements in a normal stowed position below the traffic surface and a system for raising the barricade elements from the stowed position into a position blocking vehicle traffic on the road structure in a normal traffic direction, the barricade elements being spaced apart in the traffic blocking position so the barricade is permeable to water.