Abstract:
An apparatus for placing and retrieving traffic devices in an efficient manner and with improved safety features is disclosed. The apparatus is particularly suitable for use with traffic barrels and other large items needed to block off roadway construction areas. The apparatus is also suitable for use with existing trucks, reducing the need to purchase expensive and complicated equipment, and may be adapted to allow traffic devices to be placed or retrieved from either side of the truck. The time required for placing traffic devices and the safety of operators is improved with use of the apparatus according to the invention.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to an apparatus and method for placing and retrieving safety cones, barrels, signs, barriers and other devices used as part of construction or maintenance projects on highways, roadways, streets, and parking lots that improves operator safety and efficiency. 
     2. Description of Related Art 
     Operator safety is a frequently encountered problem in highway and roadway construction projects. Safety barrels, cones, signs, barriers, and other devices are typically used to section off parts of roads where construction or maintenance projects are underway or about to be commenced to help insure the safety of workers in the work zone, to inform drivers of the construction or maintenance project, and to keep unauthorized vehicles out of the work zone. Typically, the placement of these barrels, cones, signs, barriers, and other devices is done by a combination of a truck and at least one worker walking on the road alongside the truck, with another worker in the bed or back of the truck handing the barrels, cones, signs, or other devices down to the worker on the road where they are set in place. Retrieval of these traffic devices is typically done in the same manner. However, there are safety concerns with the worker on the road, outside of the truck, as that worker is at increased risk of being hit by a passing vehicle. Additionally both workers, the one in the back or bed of the truck and the one on the road, are at increased risk of injury given the height from or to which these traffic devices have to be manually lowered or raised to get them from the truck to the road and back, particularly with some of the heavier traffic devices, such as barrels. Additionally, it takes substantial time for workers to walk alongside the truck while placing or retrieving these traffic devices, which adds to the amount of time the worker is at risk, as well as, increases the overall time the road is closed or partially blocked for completion of the construction project and placing and retrieving the traffic control devices. 
     One system for improving worker safety and decreasing the time for placing and retrieving these traffic devices is an automated conveyor type system, such as that described in U.S. Pat. No. 7,581,918 and U.S. Application Pub. No. 2010/0290880. These automated systems have the advantage of requiring fewer workers, although they do not eliminate the need for workers to be present on the truck to load or unload the traffic devices from the conveyor system and to correct any misalignment or jammed equipment during operation. They also have the drawbacks of having more mechanical parts that could become jammed or stop working during the placement or retrieval of these traffic devices and no satisfactory way of up-righting any traffic devices that fall over during placement. 
     The system described in the &#39;918 patent includes mechanisms to prevent the traffic devices from toppling or becoming misaligned, including guide rails and a topple-bar, but the topple bar has to be changed out with a topple bar of a different design to accommodate different sizes and shapes of traffic devices, such as cones with a lamp or beacon secured to the top of the cone. While the system described in the &#39;918 patent indicates it may be used for any type of traffic device, it would require substantial modification to accommodate traffic devices, such as barrels and signs, that are substantially larger than or of substantially different shape than typical traffic cones, making it impractical to use in situations where different types of traffic devices are needed. In order to retrieve the traffic devices using the automated system described in the &#39;918 patent, the truck is required to drive in reverse, which increases the danger of an accident and the possibility of traffic devices being skipped if the truck is not properly aligned with the traffic devices. 
     The system described in U.S. Application Pub. No. 2010/0290880 is suitable for use with barrels, but not cones and other lighter weight traffic devices, such as signs. Additionally, the system protrudes beyond the sides of the truck to which it is mounted, making the overall size of the vehicle much wider than usual. This increased width makes it more difficult for the truck to maneuver in tight construction areas and is more dangerous for passing vehicles. 
     Another system for improving worker safety and decreasing the time for placing these traffic devices is an automated drop type system, such as that described in U.S. Pat. No. 6,752,582. This system has the benefit of being attachable to any vehicle, but is limited to use with a particular type of flexible cone and does not accommodate barrels and other traffic devices. Additionally, this system is not suitable for retrieving cones, only placing them. 
     Several other systems with automated features are also known. These systems are available from Traf-tech (www.traftech.net), Innovative Equipment and Centreville Manufacturing, Inc. (www.innovativequip.com and www.centervilletrailer.com), SafeTcone (www.safetcone.com), and Epic Solutions (www.epicsolutions.us). These systems have many of the benefits and drawbacks of other automated systems. Although some of these systems may be mounted to existing truck or trailers, many of these systems are integrated into a heavy duty trucks and are therefore large and expensive pieces of equipment. These automated systems are suitable only for use with cones and not other traffic devices. 
     Innovative Equipment and Centreville Manufacturing, Inc. (www.innovativequip.com and www.centervilletrailer.com), also offer a trailer (the Workzone Safety Trailer) for use in the manual placement and retrieval of barrels, cones, and other traffic devices that has the benefit of not requiring a worker to be walking on the roadway. However, there are several drawbacks to this trailer system. For example, the operator has to manually lift heavy traffic devices, such as barrels, to place and retrieve them from the roadway, the operator is located at the rear end of the trailer where many vehicle collisions occur, and the trailer lacks many safety features for the operator. 
     SUMMARY OF THE INVENTION 
     The apparatus disclosed herein facilitates the placement and retrieval of various types of traffic devices with increased worker safety and efficiency. The apparatus is suitable for use with barrels, cones, signs, barriers, and other devices used as part of construction or maintenance projects to warn passing vehicles or pedestrians, block off the construction or maintenance site, protect workers in the work zone, and to keep unauthorized vehicles out of the work zone. The apparatus includes several features that increase the safety of the operators while increasing the speed with which these traffic devices may be placed or retrieved. 
     According to one embodiment of the invention, an apparatus is disclosed for placing and retrieving traffic devices using two workers or operators to move the traffic devices between a storage area on a truck to which the apparatus is attached and a roadway without requiring either operator to walk on the roadway. The areas in which the operators are located are at two different elevations, one equal or nearly equal to the elevation of the truck bed and the other closer to the roadway. The traffic devices are loaded onto a moveable platform that raises and lowers the devices between the elevations where the operators are located. 
     In a preferred embodiment of the invention, the apparatus is located along the side of the truck, between the front and rear tires, and is no wider than the widest part of the truck. The apparatus further includes safety barriers and railings to help prevent the operators from falling while the truck is operational. The apparatus also includes a set of fold-up steps or a ladder to facilitate the operator accessing the truck bed while the truck is stopped. 
     According to another embodiment of the invention, the apparatus includes two areas on the lower elevation closer to the roadway and two moveable platforms, one on each side of the truck. The elevated operator area is located between the other two operator areas. This dual-sided embodiment allows traffic devices to be placed on or retrieved from the roadway from either side of the truck, or if necessary and with an additional operator, from both sides of the truck simultaneously. Although the lower elevation area and platform for the single-sided embodiment may be located on either side of the truck, when they are on the left side the truck may have to drive the wrong-way down a roadway (under U.S. right-side driving practice) in order to place traffic devices on the right side of the road if there is not sufficient space on the shoulder or an available emergency lane. Having a dual-sided embodiment makes it easier to place traffic devices on either side of the roadway without requiring the truck to drive the wrong-way or to drive on the shoulder of the road. 
     According to other embodiments of the invention, a number of safety and convenience features are preferably included. These include a safety harness for the operator in the elevated operator area to prevent ejection from the truck, movable safety railing to help steady the operator in the elevated area during operation and to prevent falling, a safety barrier to block off access to the platform area while it is moving, a height adjustable safety rail for the operator in the lower elevation operator area, and a varying elevation for the lower operator area. 
     There are several advantages to the embodiments of the apparatus disclosed herein not previously achievable by those of ordinary skill in the art using existing technologies. These advantages include, for example, the ability place and retrieve a wide variety of traffic devices, rather than being limited to cones as in many of the prior art systems. Additionally, the apparatus may be added to an existing truck with relative ease and at little cost, thereby avoiding the cost of purchasing expensive new equipment where the system is integrated into a heavy duty truck. There are also several safety advantages, including, a reduction in worker injuries because the operators are located within the apparatus and not exposed by walking on the roadway and the risk of being hit by a passing vehicle, the operators do not have to lift the traffic devices more than a few inches, the operators have barriers and safety rails to keep them from falling on the truck bed or off the truck during operation. The apparatus also has several operational advantages, including that it may be operated in tighter construction areas because the apparatus does not protrude beyond the widest point of the truck and there are fewer moving or automated parts to malfunction or become jammed during operation. 
     The present apparatus has the disadvantage of requiring at least three workers—the two operators of the apparatus and the driver of the truck—compared to fully or semi-automated systems which require only a driver or a driver and one operator. Although this configuration increases worker costs, it is a safer system to operate. Many of the prior art automated systems use only the truck driver to operate the system, which may distract the driver and make driving the truck more dangerous. Additionally, the higher costs for additional workers are sufficiently offset by the savings and benefits achieved by increased worker safety, the speed with which traffic devices may be placed and retrieved compared to the conventional method, the lower cost of the apparatus compared to fully automated systems, the reduction in repair and maintenance costs and downtime associated with the more mechanically complex fully or semi-automated systems, and the flexibility to use the apparatus with a variety of traffic devices of different sizes and weights that cannot be achieved with automated systems. 
     It will also be appreciated by those of ordinary skill in the art upon reading this disclosure that additional features may be added to the apparatus and the apparatus may be configured or oriented in other ways within the scope of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The apparatus of the invention is further described and explained in relation to the following drawings wherein: 
         FIG. 1  is a side elevational view of one embodiment of the present invention; 
         FIG. 2  is a top plan view of the embodiment of the present invention according to  FIG. 1 ; 
         FIG. 3  is a perspective view of the embodiment of the present invention according to  FIG. 1 ; 
         FIGS. 4A and 4B  are side elevational views of a second embodiment of the present invention; 
         FIG. 5  is a top plan view of the embodiment of the present invention according to  FIG. 4 ; 
         FIGS. 6A and 6B  are more detailed top plan views of the embodiments of the present invention according to  FIGS. 4A and 4B , showing the left and right sides, respectively, in an operational configuration; 
         FIG. 7  is a perspective view of the embodiment of the present invention according to  FIG. 4 ; 
         FIG. 8  is a detailed perspective view of a first operator area and a barrier unit between the first operator area and a second operator area that are part of the embodiment of the present invention according to  FIG. 4 ; 
         FIG. 9  is a detailed side cross-sectional view of a sliding wall and cover unit that is part of the embodiment of the present invention according to  FIG. 4 ; 
         FIGS. 10 and 11  are detailed side elevational views (from the interior of the apparatus looking out) of a sliding wall and cover unit that is part of the embodiment of the present invention according to  FIG. 4 ; 
         FIGS. 12A and 12B  are detailed side cross-sectional views of an operator area and moveable platform according to another embodiment of the present invention. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       FIG. 1  depicts a side elevational view and  FIG. 3  depicts a side perspective view of a traffic device placement and retrieval apparatus  10  according to one embodiment of the present invention. The apparatus  10  is preferably attached to a modified flat-bed truck  12  wherein a portion of the bed  24  and any side walls  44  have been cut away to accommodate the apparatus  10 . The cab and other features of truck  12  depicted in the figures are to illustrate relative locations for elements of apparatus  10  (such as a front or forward direction being closer to the cab of truck  12 ), but no particular features of truck  12  are necessary for use of apparatus  10 . Apparatus  10  includes a first operator area  14  in which an operator is located and a second operator area  16  in which a second operator is located during placement and retrieval of traffic devices, such as a barrel  22 . An operator is depicted in operator area  16  on  FIG. 1 , but not in operator area  14 , for ease of demonstrating safety harness  60  (described below). The operators in areas  14  and  16  are preferably standing, but one or both may also be in a seated position. The second operator area  16  is preferably elevated relative to the first operator area  14 , with the lower surface  88  of operator area  14  being close to the roadway on which the barrel  22  is to be placed or later retrieved and the lower surface of operator area  16  being at or near the level of truck bed  24 . Operator area  14  includes sides  20  that are preferably solid surfaces to provide additional safety for the operator located in operator area  14 . These solid surfaces prevent roadway debris from being kicked up or blown into operator area  14  where they might come in contact with the operator&#39;s body. 
     Apparatus  10  also includes movable platform  32  that may be raised or lowered between positions  34  and  38 . Preferably, elevated position  38  is at or near the level of truck bed  24  and lower position  34  is at or below the bottom level of sides  20  of operator area  14 . Pulley cover  36  conceals the pulley system (not depicted) used to raise and lower platform  32 . The pulley system is similar to that used in a fork lift and those of ordinary skill in the art will understand how to modify a fork lift mechanism or to design another system to raise and lower platform  32 . Apparatus  10  also preferably includes a ladder  40  that may be lowered to allow operators to access the truck bed  24 , including operator area  16 , and may be closed and secured during operation of apparatus  10  or movement of truck  12 . Ladder  40  preferably lifts up slightly from the closed position and then slides down at an angle to allow operators to access the truck. Alternatively, ladder  40  could be hinged to fold down and up. Ladder  40  need not be configured as a traditional ladder and other step-like configurations may be used. 
     Referring to  FIG. 2 , which is a top view of apparatus  10  and truck  12  according to the embodiment in  FIGS. 1 and 3 , apparatus  10  is preferably used with truck  12  that includes a storage area  42  for storing extra traffic devices, such as barrels  22 , until they are ready to be placed on the roadway or storing the traffic devices once they have been retrieved. Truck  12  also preferably includes side walls  44  around the perimeter of truck bed  24  other than where operator area  14  and platform  32  are located. Side walls  44  keep the traffic devices in storage area  42  from falling off truck  12  and add safety for the operator located in operator area  16 . Side walls  44  also keep the operator from falling off truck  12  while the operator is in storage area  42 . Side walls  44  are preferably at least 3 feet tall and made of a semi-open or mesh-like material supported by support rails  45  spaced at intervals along the side walls  44 . Alternatively, side walls  44  may be solid or made of other materials and may be at varying heights. 
     Apparatus  10  preferably includes several barriers to provide additional safety for the operator in operator are  16 . Referring to  FIG. 2 , Barrier  50  provides separation between storage area  42  and operator area  14  and provides a hand rail for additional assistance when climbing up or down ladder  40 . Barrier  50  is preferably a bar with an open area between it and truck bed  24 . This opening under barrier  50  allows the operator in operator area  14  to easily access operator area  14  from truck bed  24  after using ladder  40  to climb up to truck bed  24 . This opening under barrier  50  also allows the operator in operator area  14  to easily access traffic devices that are stored near ladder  40 , particularly smaller or lighter weight items where the use of platform  32  is not necessary. The operator located in operator area  16  has free access to storage area  42  to obtain or return traffic devices, such as barrel  22 . When placing the traffic devices, the device is obtained from storage area  42  and placed in loading area  46  adjacent platform  32 . Barriers  30  and  31  keep the operator in operator area  16  from falling out onto the open loading area  46 , onto platform  32 , or into operator area  14 , where the operator may be injured or even fall out of the moving truck  12 . Preferably barriers  30  and  31  are around three feet high to prevent falls, but are also low enough that the operator in operator area  16  can easily bend over barrier bar  30  when loading or unloading traffic devices from loading area  46  or bend over barrier bar  31  if the operator needs to access the operator in operator area  14 . Barrier  30  is preferably a bar with an open area between it and truck bed  24  to allow traffic devices, such as barrel  22 , to easily pass underneath or around barrier  30  into the loading area  46  without the operator in operator area  16  having to lift the traffic device over barrier  30 , thereby reducing the risk of injury. Similarly, barrier  31  is preferably a bar with an open area between it and truck bed  24  to allow traffic devices to easily pass underneath or around barrier  31  into operator area  14 . This opening is useful when it is desirable to quickly place a smaller size or light weight traffic device where it would not be necessary to use platform  32 . The use of bars for barriers  30  and  31  also provide a convenient handle bar for the operator in operator area  16  to hold onto while truck  12  is moving, particularly during stopping and starting. 
     Referring to  FIGS. 1 and 3 , barrier  50  is supported by posts  52  and  53 . Barriers  30  and  31  are supported by post  33 , but post  33  may form part of either barrier if a solid or semi-solid surface is used for either barrier instead of a bar configuration. In the embodiment depicted in  FIGS. 1 ,  2 , and  3 , barriers  30  and  31  do not enclose operator area  16  or storage area  42 . There is a passage  48  (see  FIG. 2 ) so that the operator in operator area  16  may easily access loading area  46  if necessary, such as to up-right barrel  22  if it falls over before being placed on platform  32 . Alternatively, barrier bar  30  could connect to side wall  44  to enclose operator area  16  and storage area  42 , although a passage under barrier bar  30  may still be open. The open nature of the preferred barriers  30  and  31  and the preferred lower height of barriers  30  and  31  make it possible for the operator in operator area  16  to access loading area  46  or operator area  14  by going over or under the barriers  30  and  31 , preferably when truck  12  is not moving. 
     Apparatus  10  also preferably includes a safety harness system for the operator in operator area  16 . This system includes railings  54  preferably located at both ends of truck bed  24  and railing  56  located near barrier  50  in an axial direction along the length of truck  12  and above barrier  50  in a vertical direction. Railings  54  and  56  support railing  58 , which preferably is centered over the width of truck bed  24 , runs the length of truck bed  24 , and is elevated around 7 feet above truck bed  24 . Attached to railing  58  is a releasable safety harness  60  that may be strapped onto the operator in operator area  16 . Safety harness  60  is depicted as a belt-type harness, although other known harness mechanisms, such as an over-the-shoulder harness, could also be used. Safety harness  60  slides along railing  58  to allow the operator in operator area  16  to move about the back end of apparatus  10 , and particularly in storage area  42 . Safety harness  60  preferably is stopped from sliding along rail  58  toward the front of apparatus  10  by railing  56 . The length of safety harness  60  allows the operator in operator area  16  to move from operator area  16  into loading area  46 . Safety harness  60  provides additional safety for the operator in operator area  16  during movement of truck  12 , particularly in the event truck  12  has to suddenly brake or is rear-ended by another vehicle safety harness  60  prevents the operator from being ejected from truck  12 . 
     Referring to  FIGS. 1 ,  2 , and  3 , once the operator in operator area  16  has placed barrel  22  in loading area  46 , the operator in operator area  14  raises platform  32  to the elevated position  38 , if the platform is not already in that position, using controls  49 . The operator in operator area  16  then moves barrel  22  onto platform  32  and the operator in operator area  14  lowers platform  32  to its lower position  34 . The operator in operator area  14  then moves barrel  22  off platform  32  and onto the roadway or other surface where barrel  22  is to be placed. Barriers  26  and  28  provide additional safety for the operator in operator area  14  to keep the operator from falling during operation. Barrier  28  is preferably lower than barrier  26  to provide the operator in operator area  14  with additional space to bend over barrier  28  to facilitate moving barrel  22  from the platform to the roadway or other surface. The vertical location of barrier  28  is most preferably adjustable relative to barrier  26  (as shown by the alternate position in  FIG. 1 ) to accommodate operators of varying heights. A latch or pin mechanism may be used to hold barrier  28  in an elevated position. Barriers  26  and  28  are preferably bars with an open area between them and the sides  20  of operator area  14 , which provide a convenient handle bar for the operator in operator area  14  to hold onto while truck  12  is moving, particularly during stopping and starting. 
     After moving barrel  22  from platform  32  onto the roadway or other surface, the operator in operator area  14  then raises platform  32  to its elevated position  38  so that the operator in operator area  16  can load another barrel, taken from storage area  42 , from the loading area  46  to the platform. This process is repeated until all barrels or other traffic devices have been placed. To retrieve the barrels or other traffic devices, this process is repeated in reverse order. As each barrel is placed or retrieved, truck  12  moves forward along the roadway or other surface to the next location where a barrel is to be placed or retrieved (usually a few feet from the last barrel). It is not necessary for truck  12  to operate in reverse to retrieve the traffic devices. 
     Operator area  14  and platform  32  are preferably located along the side of truck  12  between the front and rear tires and do not protrude beyond the widest part of truck  12 , as depicted in  FIGS. 1 ,  2 , and  3 . These portions of apparatus  10  may also be located at the back or rear of truck  12 , with either an orientation such that operator area  14  is on the side of truck  12  or on the rear end of truck  12 , with modifications understood by those of ordinary skill in the art. As many vehicle collisions involve rear end impacts, the operator in operator area  14  is at greater risk if these portions of apparatus  10  are located at the back or rear of truck  12  and particularly if operator area  14  is oriented on the rear end of truck  12  rather than the side of truck  12 . Thus the location and orientation of operator area  14  and platform  32  along the side of truck  12  and near the front of truck  12  is preferred. 
       FIGS. 4A and 4B  depict side elevation views of traffic device placement and retrieval apparatus  110  according to another embodiment of the present.  FIGS. 5 and 6A  and  6 B show top views of apparatus  110  at varying elevations and  FIG. 7  shows a perspective view of apparatus  110  as depicted in  FIGS. 4A ,  5  and  6 A. Apparatus  110  is similar to apparatus  10  except that it has left and right operator areas  114 L and  114 R, left and right platforms  132 L and  132 R, left and right pulley systems covered by pulley covers  136 L and  136 R, and left and right ladders  140 L and  140 R located on both sides of truck  112 . Operator area  116  is located between operator areas  114 L and  114 R and loading area  146  is located between platforms  132 L and  132 R. The dual sided configuration of apparatus  110  is the most preferred embodiment of the invention. 
     Most of the preferred features described with respect to apparatus  10  are the same for apparatus  110 . Referring to  FIGS. 4A ,  4 B,  5 , and  7 , apparatus  110  is preferably attached to a modified flat-bed truck  112  wherein a portion of the bed  124  and any side walls  144  have been cut away to accommodate the apparatus  110 . The cab and other features of truck  112  depicted in the figures are to illustrate relative locations for elements of apparatus  110  (such as a front or forward direction being closer to the cab of truck  112 ), but no particular features of truck  112  are necessary for use of apparatus  110 . Apparatus  110  includes right and left side operator areas  114 L and  114 R in which an operator or operators are located and a third operator area  116  in which a second or third operator is located during placement and retrieval of traffic devices, such as a barrel  122 . Operator area  116  is preferably elevated relative to the left and right operator areas  114 L and  114 R, with the lower surfaces  188 L and  188 R of operator areas  114 L and  114 R being close to the roadway on which the barrel  122  is to be placed or later retrieved and the lower surface of operator area  116  bear at or near the level of truck bed  124 . Operator areas  114 L and  114 R includes sides  120  that are preferably solid surfaces to provide additional safety for the operator located in operator areas  114 L and  114 R. 
     Apparatus  110  also includes left and right movable platforms  132 L and  132 R that may be raised or lowered between positions  134  and  138 . Preferably, elevated position  138  is at or near the level of truck bed  124  and lower position  134  is at or near the bottom level of sides  120  of operator areas  114 L and  114 R. Left and right pulley covers  136 L and  136 R conceal the pulley system (not depicted) used to raise and lower left and right platforms  132 L and  132 R. Apparatus  110  also preferably includes left and right ladders  140 L and  140 R that may be lowered to allow operators to access the truck bed, including operator area  116 , and may be closed and secured during operation of apparatus  110  or movement of truck  112 . Ladders  140 L and  140 R preferably lift up slightly from the closed position and then slide down at an angle to allow operators to access the truck. Alternatively, ladders  140 L and  140 R could be hinged to fold down and up. Ladders  140 L and  140 R need not be configured as a traditional ladder and other step-like configurations may be used. 
     Referring to  FIG. 5 , which is a top view of apparatus  110  according to the embodiment in  FIGS. 4A ,  4 B, and  7 , apparatus  110  is preferably used with truck  112  that includes a storage area  142  for storing extra traffic devices until they are ready to be placed on the roadway or storing the traffic devices once they have been retrieved. Truck  112  also preferably includes side walls  144  around the perimeter of truck bed  124  other than where operator areas  114 L and  114 R and platforms  132 L and  132 R are located. Side walls  144  keep the traffic devices in storage area  142  from falling off truck  112  and add safety for the operator located in operator area  116 . Side walls  144  are preferably at least 3 feet tall and made of a semi-open or mesh-like material supported by support rails  145  spaced at along the side walls  144 . Alternatively, side walls  144  may be solid or made of other materials and may be at varying heights. 
     Apparatus  110  preferably includes several barriers to provide additional safety for the operator in operator area  116 . Referring to  FIGS. 6A and 6B , barrier  150  provides separation between storage area  142  and operator area  114 L (or  114 R, depending on which side is in use, as barrier  150  is movable as described below) and provides a hand rail for additional assistance when climbing up or down ladder  140 L (or  140 R). Barrier  150  is preferably a bar with an open area between it and truck bed  124 . This opening under barrier  150  allows the operator in operator area  114 L (or  114 R) to easily access operator area  114 L (or  114 R) from truck bed  124  after using ladder  140 L (or  140 R) to climb up to truck bed  124 . This opening under barrier  150  also allows the operator in operator area  114 L (or  114 R) to easily access traffic devices that are stored near ladder  140 L (or  140 R), particularly smaller or lighter weight items where the use of platform  132 L (or  132 R) is not necessary. The operator located in operator area  116  has free access to storage area  142  to obtain or return traffic devices, such as barrel  122 . When placing the traffic devices, the device is obtained from storage area  142  and placed in loading area  146  located between platforms  132 L and  132 R. 
     Barriers  130  and  131  keep the operator in operator area  116  from falling out onto the open loading area  146 , onto platform  132 L (or  132 R), or into operator area  114 L (or  114 R) where the operator may be injured or even fall out of the moving truck  112 . Preferably barriers  130  and  131  are around three feet high to prevent falls, but are also low enough that the operator in operator area  116  can easily bend over barrier bar  130  when loading or unloading traffic devices from loading area  146  or bend over barrier bar  131  if the operator needs to access the operator in operator area  114 L (or  114 R). Barrier  130  is preferably a bar with an open area between it and truck bed  124  to allow traffic devices, such as barrel  122 , to easily pass underneath or around barrier  130  into the loading area  146  without the operator in operator area  116  having to lift the traffic device over barrier  130 , thereby reducing the risk of injury. Similarly, barrier  131  is preferably a bar with an open area between it and truck bed  124  to allow traffic devices to easily pass underneath or around barrier  131  into operator area  114 L (or  114 R). This opening is useful when it is desirable to quickly place a smaller size or light weight traffic device where it would not be necessary to use platform  132 L (or  132 R). The use of bars for barriers  130  and  131  also provide a convenient handle bar for the operator in operator area  116  to hold onto while truck  112  is moving, particularly during stopping and starting. 
     Referring to  FIGS. 6A ,  6 B, and  7 , barrier  150  is supported by posts  153 L or  153 R (depending on which side of apparatus  110  is in use). Barriers  130  and  131  are supported by post  133 , but post  133  may form part of either barrier if a solid or semi-solid surface is used for either barrier instead of a bar configuration. Barriers  130  and  131  do not enclose operator area  116  or storage area  142 . There is a passage  148 L or  148 R (see  FIGS. 6A and 6B ) so that the operator in operator area  116  may easily access loading area  146  if necessary, such as to up-right barrel  122  if it falls over before being placed on platform  132 L (or  132 R). Alternatively, barrier bar  130  could extend nearly to or connect to sliding wall  174 R (or  174 L, discussed below) to enclose operator area  116  and storage area  142 , although a passage under barrier bar  130  may still be open. The open nature of the preferred barriers  130  and  131  and the preferred lower height of barriers  130  and  131  make it possible for the operator in operator area  116  to access loading area  146  or operator area  114 L (or  114 R) by going over or under the barriers  130  and  131 , preferably when truck  112  is not moving. The use of bars for barriers  130  and  131  also provide a convenient handle bar for the operator in operator area  116  to hold onto while truck  112  is moving, particularly during stopping and starting. 
     To allow for operation with either the left side or right side operator areas  114 L and  114 R of apparatus  110 , barriers  130 ,  131 ,  150  and posts  133  and  152  are movable. When the left side operator area  114 L is in use, as depicted in  FIG. 6A , barriers  130 ,  131 , and  150  are in the same location as depicted for barriers  30 , barriers  30 ,  31 , and  50  on apparatus  10 . However, when the right side operator area  114 R is in use, as depicted in  FIG. 6B , these barriers are relocated to the other side of truck  112 . 
       FIG. 8  is a detailed view of these barriers and their supporting posts  133  and  152  showing how they are movable as a single barrier unit  170  for use on either side of truck  112 . In apparatus  110 , barrier  130  is hinged to post  133  by hinge  166  and barrier  150  is hinged to post  152  by hinge  164 . Barrier  131  is attached to posts  133  and  152  in a fixed manner, such as by welding or bolting, so that barrier  131  does not move during relocation of barrier unit  170  and adds stability to barrier unit  170 . Additional bar  168 , located below barrier  131 , is attached to posts  133  and  152  in a fixed manner, such as by welding or bolting. Apparatus  110  includes pockets  162  and  163  located in operator areas  114 L (similar pockets are included on operator area  114 R, although they are not depicted) Pockets  162  and  163  are preferably located in the interior corners (relative to the interior of truck  112 ) of operator areas  114 L and  114 R, with the top openings of these pockets located at or near the level of truck bed  124  (see also pocket  162  as depicted in  FIG. 7 ). Pocket  162  holds posts  133  and pocket  163  holds post  152 , allowing the posts to be removed and placed in corresponding pockets located in operator areas  114 L and  114 R on either side of truck  112 . Bar  168  is preferably located on posts  133  and  152  between barrier  131  and the lower ends of posts  133  and  152 , in a vertical position that allows sufficient length of posts  133  and  152  to slip into pockets  162  and  163  to hold barrier unit  170  securely in place. When the posts are placed in the pockets, bar  168  rests on the top of pockets  162  and  163  to prevent the barrier unit  170  from slipping downward and to maintain barriers  130 ,  131 , and  150  at an appropriate height for the safety of the operator in operator area  116 . Pockets  162  and  163  could also have solid bottoms to prevent barrier unit  170  from slipping downwards, but the use of bar  168  is preferred for added stability to barrier unit  170 . 
     Pockets  162  and  163  may also have holes at varying heights to correspond with holes located on posts  133  and  152 , to allow adjustment of the height of barrier unit  170  by insertion of a pin through the holes at the desired height. As shown in  FIG. 8 , barriers  130  and  152  are in the operational position for use with operator area  114 L (see also  FIG. 6A ). When barrier unit  170  is moved to the right side of the truck  112  by inserting posts  133  and  152  into pockets  162  and  163  located in operator area  114 R, barriers  130  and  150  are flipped 180° using hinges  166  and  164  to align properly with operator area  114 R and  116 , as depicted in  FIG. 6B . Posts  153 L and  153 R, located on both sides of truck  112 , are preferably fixed near the rear side of operator areas  114 L and  114 R and the exterior sides of truck  112  and provide support for barrier  150 . 
     Apparatus  110  also preferably includes a safety harness system for the operator in operator area  116 . This system includes railings  154  preferably located at both ends of truck bed  124  and railing  156  located near barrier  150  in an axial direction along the length of truck  112  and above barrier  150  in a vertical direction. Railings  154  and  156  support railing  158 , which preferably is centered over the width of truck bed  124 , runs the length of truck bed  124 , and is elevated around 8 feet above truck bed  124 . Attached to railing  158  is a releasable safety harness  160  that may be strapped onto the operator in operator area  116 . Safety harness  160  is depicted as a belt-type harness, although other known harness mechanisms, such as an over-the-shoulder harness, could also be used. Safety harness  160  slides along railing  158  to allow the operator in operator area  116  to move about the back end of apparatus  110 , and particularly in storage area  142 . Safety harness  160  preferably is stopped from sliding along rail  158  toward the front of apparatus  110  by railing  156 . The length of safety harness  160  allows the operator in operator area  116  to move from operator area  116  into loading area  146 . Safety harness  160  provides additional safety for the operator in operator area  116  during movement of truck  112 , particularly in the event truck  112  has to suddenly brake or is rear-ended by another vehicle safety harness  160  prevents the operator from being ejected from truck  112 . 
     Referring to  FIGS. 4A ,  4 B,  5 , and  7 , once the operator in operator area  116  has placed barrel  122  (or other traffic device) in loading area  146 , the operator in operator area  114 L (or  114 R, depending on which side of apparatus  110  is being used) raises platform  132 L (or  132 R) to the elevated position  138 L (or  138 R), if the platform is not already in that position, using controls  149 L (or  149 R). The operator in operator area  116  then moves barrel  122  onto platform  132 L (or  132 R) and the operator in operator area  114 L (or  114 R) lowers platform  132 L (or  132 R) to its lower position  134 L (or  134 R). The operator in operator area  114 L (or  114 R) then moves barrel  122  off platform  132 L (or  132 R) and onto the roadway or other surface where barrel  122  is to be placed. 
     Barriers  126  and  128  provide additional safety for the operator in operator area  114 L (or  114 R) to keep the operator from falling during operation. Barrier  128  is preferably lower than barrier  126  to provide the operator in operator area  114 L (or  114 R) with additional space to bend over barrier  128  to facilitate moving barrel  122  from the platform to the roadway or other surface. The vertical location of barrier  128  is most preferably adjustable relative to barrier  126  (as shown by the alternate position in  FIGS. 4A and 8 ) to accommodate operators of varying heights. A latch or pin mechanism may be used to hold barrier  128  in an elevated position. Barriers  126  and  128  are preferably bars with an open area between them and the sides  120  of operator area  114 L (or  114 R), which provide a convenient handle bar for the operator in operator area  114 L (or  114 R) to hold onto while truck  112  is moving, particularly during stopping and starting. 
     After moving barrel  122  from platform  132 L (or  132 R) onto the roadway or other surface, the operator in operator area  114 L (or  114 R) then raises platform  132 L (or  132 R) to its elevated position  138 L (or  138 R) so that the operator in operator area  116  can load another barrel, taken from storage area  142 , from the loading area  146  to the platform. This process is repeated until all barrels or other traffic devices have been placed. To retrieve the barrels or other traffic devices, this process is repeated in reverse order. As each barrel is placed or retrieved, truck  112  moves forward along the roadway or other surface to the next location where a barrel is to be placed or retrieved (usually a few feet from the last barrel). It is not necessary for truck  112  to operate in reverse to retrieve the traffic devices. 
     Operator areas  114 L and  114 R and platforms  132 L and  132 R are preferably located along the side of truck  112  between the front and rear tires and do not protrude beyond the widest part of truck  112 , as depicted in  FIGS. 4 ,  5 , and  7 . These portions of apparatus  110  may also be located at the rear of truck  112 , with modifications understood by those of ordinary skill in the art. As many vehicle collisions involve rear end impacts, the operator in operator area  114 L or  114 R is at greater risk if these portions of apparatus  110  are located at the rear of truck  112 . Thus the location and orientation of the portions of apparatus  110  along the sides of truck  112  and near the front of truck  112  are preferred. 
     It is possible to use both operator areas  114 L and  114 R and platforms  132 L and  132 R at the same time according to the invention, if there were a need to place or retrieve traffic devices on both sides of truck  112  simultaneously. For use on both sides simultaneously, a second barrier unit  170  is provided to allow barriers to be in place on both sides for the safety of the operator or operators in operator area  116 . If two operators are located in operator area  116 , a second safety harness  160  may also be used. When not in use, the second barrier unit and second safety harness may be stored in storage area  142 . 
     Referring to  FIGS. 6A ,  6 B, and  7 , apparatus  110  includes floor covers  172 L and  172 R and sliding walls  174 L and  174 R on both sides of apparatus  110  to add to the safety and usefulness of the dual-sided embodiment of apparatus  110 . When the left side operator area  114 L is in use, sliding wall  174 R and floor cover  172 R are slid into the area adjacent operator area  114 R and platform  132 R. Floor cover  172 R is lowered to cover the opening for the right side operator area  114 R and right side platform area  132 R (as depicted in  FIG. 6A ), while sliding wall  174 R covers the opening in side wall  144  in those areas. When the right side operator area  114 R is in use, sliding wall  174 L and floor cover  172 L are slid into the area adjacent operator area  114 L and platform  132 L. Floor cover  172 L is lowered to cover the opening for the left side operator area  114 L and left side platform area  132 L (as depicted in  FIG. 6B ), while sliding wall  174 L covers the opening in side wall  144  in those areas. When in the lowered position, floor covers  172 L and  172 R provide usable work space and a flooring surface suitable for walking on or storing items and also prevent the operator in operator area  116  from falling into the open spaces. When in the closed position, sliding walls  174 L and  174 R also prevent items placed in loading area  146  and the operator in operator area  116  from falling out of truck  112 , or onto platform areas  132 L or  132 R or into operator areas  113 L or  114 R. Floor cover  172 R (or  172 L) is preferably in the raised position when sliding wall  174 R (or  174 L) is in the open position and in the lowered position when sliding wall  174 L (or  174 R) is in the closed position. 
     Sliding walls  174 L and  174 R slide along the sides of apparatus  110  in top tracks  176 L and  176 R (as depicted in  FIGS. 7 and 9 ) and bottom tracks  178 L and  178 R (as depicted in  FIGS. 6A and 6B ). Top track  176 L extends from pulley cover  136 L toward the rear of apparatus  110  for a sufficient distance to support sliding wall  174 L when it is in the open position. Bottom track  178 L extends from the rear of operator area  114 L backward for a sufficient distance to support sliding wall  174 L when it is in the open position, but preferably does not extend further forward to avoid interfering with barriers  126  and  128  in operator area  114 L or platform  132 L. These same features apply to the right side cover  172 R, sliding wall  174 R, top track  176 R, and bottom track  178 R. When in the raised position, cover  172 L (or  172 R) is preferably secured to sliding wall  174 L (or  174 R) with a latch  181  so that they slide together as a single unit. Sliding wall also has a side latch  179  to secure it in place in either an open or closed position. Similar latches are used for sliding wall  174 R and floor cover  172 R. When sliding walls  174 L and  174 R are in the open position (see  FIGS. 6A and 6B ), floor cover  172 L and  172 R are in the raised position and the whole unit is stored in the rear of truck  112  adjacent storage area  142 . Again, it is possible to use both operator areas  114 L and  114 R and platforms  132 L and  132 R at the same time, with the sliding walls  174 L and  174 R both in the open position (and floor covers  172 L and  172 R in the raised and secured positions). 
       FIG. 9  shows a detailed view of floor cover  172 R in its raised and lowered positions. Floor cover  172 R is preferably hinged to sliding wall  174 R by hinge  180 R (and cover  172 L is preferably hinged to sliding wall  174 L by a similar hinge, which is not depicted) to facilitate raising and lowering the floor cover.  FIG. 10 . also shows a detailed view of sliding wall  174 R in its closed position (from a perspective inside truck  112  looking out, when operator area  114 R is not in use) and floor cover  172 R in its raised position, just before it is lowered.  FIG. 11  shows another detailed view of sliding wall  174 R in its closed position (from a perspective inside truck  112  looking out, when operator area  114 R is not in use) and floor cover  172 R in its lowered position. 
       FIGS. 12A and 12B  are cross-sectional detailed views of a platform and first operator area according to another preferred embodiment of the invention. Although  FIGS. 12A and 12B  refer to the left side aspects of apparatus  110 , it is understood that each of the features depicted are also preferably included in platform  132 R and operator area  114 R.  FIG. 12A  shows platform  132 L in its lowered position  134  for moving traffic device  122  from apparatus  110  to the roadway or from the roadway onto apparatus  110 .  FIG. 12B  shows platform  132 L in its raised position  138  for moving traffic device from loading area  146  onto platform  132 L or from platform  132 L into loading area  146 . Pulley system  182 , which is preferably a modified fork lift system, is also depicted in  FIGS. 12A and 12B . As platform  132 L moves from lower position  134  to raised position  138 , a lip  186  catches safety shield  184 , lifting safety shield  184  up to cover over the opening between barriers  126  and  128  and side  120  of operator area  114 L (see also  FIG. 7 ). As platform  132 L is lowered, safety shield  184  is also lowered to uncover the opening. Safety shield  184  prevents objects, such as the hands of the operator in operator area  114 L, from being caught by platform  132 L while it is moving. 
     Operator area  114 L also has a movable bottom surface  188 . When the operator enters operator area  114 L and puts weight on bottom surface  188 , springs  196  allow bottom surface  188  to move downward to allow the operator to be closer to the roadway where traffic device  22  is to be placed or from which it is to be retrieved, as shown in  FIG. 12B . The downward motion is limited by lip  190  which catches on bar  192  to prevent bottom surface  188  from moving too close to the roadway. When the operator exits operator area  114 L and the weight is removed, bottom surface  188  returns to its original position, as shown on  FIG. 12A . The raised, original position for bottom surface  188  helps prevent it from catching on any debris that may be in the roadway, particularly when truck is moving at full speed and the operator areas are not in use. Bottom surface  188  is stabilized during vertical movement by rods  198  inserted through holes in bottom surface  188 , so that bottom surface  188  slides along the rods  198  when moving up and down. The features depicted in  FIGS. 12A and 12B  are preferably also used in operator area  14  and platform  32  of apparatus  10 . 
     As used herein, references to traffic devices include cones, barrels, signs, barriers, and other devices used as part of construction or maintenance projects on highways, interstates, roadways, streets, and parking lots to provide warning or notice to passing vehicles and pedestrians, block-off the work zone, or prevent unauthorized vehicles or persons from entering the work zone. References to a truck herein are not intended to be limiting and include any type of vehicle suitable for placing and retrieving traffic devices. Additionally, references to a road, highway, or roadway herein are not intended to be limiting and include any type of surface on which traffic devices may be placed, including parking lots. 
     Other alterations and modifications of the invention will be apparent to those of ordinary skill in the art upon reading this specification in view of the accompanying drawings, and it is intended that the scope of the invention disclosed herein be limited only by the broadest interpretation of the appended claims to which the inventor is legally entitled.