the present invention provides a safe , reliable and economical correlator system for an automatic car wash . the correlator system is used in an automatic car wash move the front wheels of an automotive vehicle into a position of alignment with the conveyor mechanism that drives the car through the machinery of the car wash . the conveyor system carries the front and left wheels of the car while the right wheels coast along through the car wash . it is a necessary prerequisite that the left wheels of a vehicle appointed for passage through the car wash be substantially parallel to and aligned with the conveyor track . this is accomplished by the correlator . in general , land vehicles brought into a car wash are not precisely in alignment with the car wash conveyor track . this misalignment typically takes the form of axial displacement or angular misalignment . in order to overcome this problem , most car wash facilities utilize a correlator , which is provided with a bed of free - to - rotate , low friction rollers located directly below the front left wheel and front right wheel of a vehicle appointed for alignment with the car wash conveyor . the left wheel portion of the correlator is provided with two guide bars that are inclined to each other , forming a capture region that is larger than the exit region . the guide bars exit region is spaced at a distance equal to the conveyor traction device . due to the larger distance between the guide bars at the entrance region , the left wheel is captured regardless of axial displacement or angular misalignment . the left wheel contacts the guide bars and is coaxed into alignment — a process that requires axial displacement of the vehicle &# 39 ; s front end and correction of angular misalignment . such a process is carried out by the rotation of rollers directly below the vehicle &# 39 ; s front left and right wheels . this task is accomplished by housing the rollers within a sleeve especially adapted to provide a low - friction bearing support that limits application of stresses to the front end of the automotive vehicle . the rollers and the shaft supporting the rollers are made from corrosion resistant stainless steel or galvanized steel that works reliably in a car washing environment involving use of aggressive , corrosive fluids . in the past packed ball bearings have been used to support the stainless steel or galvanized steel roller shaft . oftentimes , corrosion causes these bearings to stick ; and the car washing operation stops when the incoming vehicles are not properly aligned with the conveyor track . recent developments have resulted in the use of ultra high molecular weight ( uhmw ) polyethylene sleeve bearings that provide for rotation of the rollers with very little or minimal friction . these uhnw sleeve bearings operate without need for any lubrication such as grease or oils . further , the low friction properties of these bearings are maintained even under wet conditions with aggressive cleaning chemicals . the use of uhmw sleeve bearings have become standard in the industry as evidenced by car wash machinery manufacturers such as sonny , mcneil , peco and the like . unfortunately , the very same low friction rotation properties of the rollers causes a severe injury hazard for workers who sometimes need to cross the car washing line to inspect or fix jet locations etc . stepping on these low friction rollers causes loss of balance . workers that fall in this environment can be injured by contact with large protruding objects such as guide rolls , and the like . such inadvertent contact can , in turn , result in bone fractures , concussions and other injuries that present severe worker health consequences . the present invention provides friction generating elements for each of the correlator rollers that support the vehicle &# 39 ; s front left and right wheels . the magnitude of the friction generated is adequate to prevent turning of the rollers under the weight of a car wash worker . on the other hand , it is inadequate to prevent roller rotation in response to the weight of a vehicle &# 39 ; s front end . the relatively large differential between the weight of a human as compared to the weight of an automotive vehicle is used to create , in effect , a braking — non - breaking condition . the friction generating element may be a tangential braking element or a radial braking element . the tangential braking system takes the form a spring loaded , pivotable plate which contacts the circumference of a roller to retard its rotation . a radial braking system comprises a spring loaded , curved element , similar to a segment of a circle , which contacts either the interior or the exterior surface of a roller . in the first embodiment of the invention , the friction generating elements are attached to each of the rollers supporting the left and right wheel of an automobile appointed for passage through the automatic car wash . these rollers are positioned essentially parallel to each other in a manner conventional with commercial car washing machines , such as those produced by peco , sonny or mcneil , for example . preferably , the friction generating element is a tangential brake . a pivotable spring loaded plate contacts the external circumferential surface of a roller , retarding its rotation in response to a load equivalent to a person stepping on the roller . the spring constant of the spring is selected to provide this required friction . however , such friction is insufficient to prevent roller rotation when a land vehicle is driven onto the roller set . in such a case , the rollers rotate freely while the vehicle undergoes adjustment , including axial displacement and angular alignment in response to lateral forces exerted thereon by the correlator guide bars . in the second embodiment of the invention , the friction generating elements are attached to each of the rollers supporting the left and right wheel of an automobile appointed to enter the automatic car wash process . these rollers are slightly inclined with respect to each other , so that a larger distance exists between the rollers at the entrance capture portion of the correlator . the distance between the rollers decreases at the exit portion of the correlator , where the automobile left front wheel is delivered to the conveyor track . due to the angle between the rollers , the left front wheel contacts rollers in a sequence instead of using one single roller . this distributes the load of the vehicle , reducing the wear of rollers and their support bearings and prolonging correlator service life . due to the improved service life of the uhme sleeve bearings , reduced friction is realized . the set of rollers supporting the front right wheel may also be inclined in the manner of the set of rollers supporting the left front wheel . this construction is intended for use in lieu of a construction wherein the correlator comprises a set of substantially parallel rollers . rollers of this configuration are not utilized in commercial car washing machines such as those produced by peco , sonny or mcneil . preferably , the friction generating element for each of these inclined rollers is a tangential brake . in such braking apparatus , a pivotable spring loaded plate contacts the external circumferential surface of a roller , retarding its rotation at a load equivalent to a person stepping on the roller . the force constant of the spring is selected to provide this required friction . on the other hand , such friction is insufficient to prevent rotation of the roller when the automobile vehicle is driven on the roller set and is adjusted to effect axial displacement and angular alignment in response to lateral forces exerted thereon by the guide bars . fig1 illustrates generally at 10 a conventional correlator system of the type used by peco , sonny or mcneil car washing systems . an automobile vehicle &# 39 ; s left front wheel enters the correlator along the direction of the arrow at 11 aided by entrance guide rail bumpers . the automobile vehicle exits the correlator in alignment with the conveyor track at 12 along the direction of the arrow , proceeding into the car wash machinery . the guide rails or bars 13 adjust the axial displacement of the left front wheel and its angular misalignment so that the left wheel of the automobile vehicle aligns with the conveyor track at 12 with supporting guide rails . the left side front wheels of the land vehicles are supported by a plurality of rollers 14 mounted on low friction uhmw polyethylene sleeve bearings ( not shown ). these rollers are arranged substantially parallel to each other and are oriented in the travel direction of the vehicle into the car washing machine , as indicated by the arrow . similarly , the right side front wheel of the vehicle is supported on a plurality of similar parallel rollers 15 . like rollers 14 , the rollers 15 are substantially parallel to the vehicle travel direction and are supported by a set of low friction uhmw polyethylene sleeve bearings . when the left wheel is coerced for axial displacement or correction of angular misalignment by the guide rails or bars 13 , the front end of the automobile vehicle moves left to right and the wheels are turned by the rotation of these supporting rollers 14 , 15 . the portion between the left wheel supporting and right wheel supporting roller assembly is a conventional diamond steel plate 16 . the force needed for this adjustment is relatively low , due to the low friction rotational characteristics of the supporting rollers . once the front end is properly positioned , the rear wheels simply follow along onto the conveyor track . conventional correlator rollers are free to rotate at minimal loading . consequently , persons attempting to walk over the rollers will likely lose their footing and fall , thereby incurring an injury . fig2 shows generally at 20 a partial photograph of the driving surface of the rollers for the left front wheel support or right front wheel support according to the subject invention . the guide rails or bars are attached with this roller arrangement , when it is used for supporting the left wheel of the automobile vehicle . each of the rollers 14 or 15 is provided with a friction generating element . in the embodiment shown by fig2 , there is used a tangential friction element comprising a spring loaded pivotable plate 22 , which contacts the circumferential outer surface 23 of the roller , retarding its rotation when stepped on by a person walking across the car wash line . fig3 shows generally at 30 a photograph of the reverse surface of the correlator &# 39 ; s rotating rollers , showing the details of the pivotable plate and its spring loading . due to this spring loading , a tangential force is applied to the circumferential external surface of each roller , generating friction that prevents injury to a car wash worker . the frame of the roller retainer is shown at 31 . the bearing mechanism for the rollers , shown at 32 , comprises a uhmw polyethylene sleeve bearing and an end cap . a pivot bolt and nut 33 are used for attaching a pivotable plate 34 . the plate 34 has a circular hole formed therefrom . a flat portion and the pivot bolt passes through the circular hole forming a pivot for the plate , while the flat portion of the plate contacts the external circumferential surface of a roller 14 or 15 . a spring 35 loads the pivotable plate and is attached at one end to the plate 34 and to a bolt 36 , as shown . fig4 shows at 40 a photograph of the second embodiment of the invention wherein the rollers 14 , 15 are inclined to each other instead of being parallel , as depicted in fig1 . the wider portion is at the entrance to the correlator , while the exit portion that delivers the automobile left front wheel to the conveyor belt is disposed at the narrower end . the frame of the rollers for either left front wheel support or right front wheel support is shown at 31 . the rollers 14 or 15 are clearly inclined to each other . the line 42 indicates the general driving direction of the vehicle onto the correlator . the bottom portion of the correlator 43 indicates the entry point of the vehicle onto the correlator . upon undergoing lateral adjustment and alignment , the vehicle exits correlator 43 at the top portion 44 . the friction generating elements are shown at 45 , and are located well below the driving surface of the correlator assembly . due to this inclination of the rollers , the wheel contacts different rollers as it moves forward , distributing the loading to adjacent rollers one at a time and thereby reducing wear on the uhmw polyethylene bearing and prolonging the in - service life of the correlator mechanism . fig5 is a photograph showing generally at 50 the reverse side of the inclined roller configuration depicted by fig4 . the frame of the roller assembly is shown at 31 and supports rollers 14 or 15 . the friction generating mechanism 51 comprises a spring loaded pivotable plate in contact with the external circumferential surface of the roller , as detailed in fig3 . the safe , reliable automatic car wash correlator system comprises the following features , in combination : 1 ) a plurality of low friction easy to roll steel rollers mounted on a frame , forming a roller assembly located between a vehicle entrance and a conveyor track ; 2 ) said low friction being provided by ultra high molecular weight ( uhmw ) polyethylene steel bearings , which support steel shafts of the steel rollers ; 3 ) the rollers being oriented essentially along the direction of travel of a land vehicle into a car wash station , and supporting the vehicle &# 39 ; s left and right front wheels ; 4 ) each roller of said roller assembly being provided with a friction generating element adapted to generate sufficient frictional force to retard the rotation of said rollers when a car wash worker steps on said roller assembly ; 5 ) said frictional force being insufficient to prevent the rotation of said rollers when a land vehicle &# 39 ; s left front wheel is being aligned with a conveyor track ; 6 ) said friction generating element comprising a tangential brake having a spring loaded pivotable plate adapted to contact the external circumferential surface of the roller retarding rotation when stepped on by a car wash worker ; 7 ) said friction generating element comprising a radial brake having curved shoe brakes contacting interior or exterior circular surface portions of said rollers ; 8 ) said rollers being substantially parallel to each other ; 9 ) said rollers being inclined to each other with the wider end of roller assembly residing at the entrance to the car wash and the narrow end residing at the entrance to the conveyor track ; whereby the left front wheel of the automobile vehicle in contact with a roller assembly and the right front wheel on a second roller assembly are guided by guide rails or bars to the conveyor track by lateral forces operative to adjust axial displacement or angular misalignment . having thus described the invention in rather full detail , it will be understood that such detail need not be strictly adhered to , but that additional changes and modifications may suggest themselves to one skilled in the art , all falling within the scope of the invention as defined by the subjoined claims