US 3896414 A
Description (OCR text may contain errors)
United States Patent [1 1 Rule [ ROADWAY DETOUR SYSTEM FOR VEHICLES  Inventor: Charles J. Rule, 2i [3 Stansbury, St. Louis, Mo. 63118 22 Filed: July 11, 1973 211 Appl. No; 378,254
 US. Cl. 340/31 R; 250/222 R [5 1] Int. Cl G08g 1/04  Field of Search 340/31 R, 38 P  References Cited UNITED STATES PATENTS 3,275,984 9/1966 Barker 340/31 R FOREIGN PATENTS OR APPLICATIONS 420,393 ll/l934 United Kingdom 340/38 P 1 July 22, 1975 Primary ExaminerWilliam C. Cooper Attorney, Agent, or Firm-John D. Pope, [ll
 ABSTRACT A system to direct a vehicle off a roadway when there is insufficient clearance between the vehicle and a nearby overpass includes a height sensing device in combination with a detour signal device that directs the vehicle off the roadway. The height sensing device transmits a beam of light across a roadway to a photocell. The beam of light is at a predetermined height over the roadway and is subject to interruption by a vehicle that exceeds this predetermined height. The detour signal device, which is located a predetermined distance from the height sensing device, is activated when the light beam is interrupted and directs the vehicle toward an exit from the roadway to an alternate safe route.
9 Claims, 4 Drawing Figures ROADWAY DETOUR SYSTEM FOR VEHICLES This invention is directed to new and useful improvements in traffic control systems and more particularly to a roadway detour system for directing a vehicle to an alternate route when there is insufficient clearance between the vehicle and a nearby overpass or similar obstruction.
Almost every roadway in use today leads into tunnels or beneath bridges, traffic ramps, railway tressels and elevated highways, etc., all of which can be generally referred to as overpasses. It is well known that many of these overpasses do not have sufficient height to safely clear unusually tall vehicles, particularly trucks.
Generally, signs or other warning devices are posted in advance of the overpasses indicating the maximum safe vehicle height which the overpass can safely accomodate. Despite such warnings, accidents due to in sufficient clearance between vehicles and overpasses remain a continuing problem.
Proposed solutions to this problem include providing radio transmitters on overpasses and equipping vehicles with special warning receivers. This is an expensive approach to the problem and would require the receivers in moving vehicles to be in continuous operation. Another proposed solution includes equipping a vehicle with an overpass clearance detector switch operable to warn a driver of insufficient clearance when the vehicle is already at the overpass. This device does not solve the problem if the vehicle is traveling too fast to stop before the overpass. Furthermore, even if the vehi cle is safely stopped in advance of the overpass. the driver is normally in an equally dangerous predicament of detouring his vehicle in the face of oncoming traffic.
It is thus desirable to provide a roadway detour system for directing the vehicle to a safe exit or detour from the roadway before the vehicle comes to an overpass having insufticient clearance.
Among the several objects of the present invention my be noted the provision of a novel roadway detour system for directing a vehicle away from an overpass; a novel roadway detour system that does not require installation of special equipment on those vehicles which the detour system is designed to protect; a novel roadway detour system that can be actuated into operation by a vehicle that will not safely clear a nearby overpass; and a novel detour system that forms a part of the roadway system and is arranged to operate only when a vehicle exceeds a predetermined height. Other objects and features will be in part apparent and in part pointed out hereinafter.
The present invention relates to a novel roadway detour system having a detour signal which can be actuated into operation by a vehicle as it passes a checkpoint, if the vehicle exceeds a predetermined height. In one embodiment the invention comprises a device for sensing the height of a vehicle in combination with a device for providing a detour signal when required.
The height sensing device which includes a light beam transmitter and a light sensing element produces a beam of light at a predetermined height across the roadway. A vehicle exceeding this predetermined height will interrupt the light beam to activate the detour signal device.
The detour signal device comprises a signal light having those colors conventionally used to slow down and- /or stop the movement of traffic. The detour signal lights can be arranged in the shape of arrows for exampie to direct the vehicle with excessive height to a roadway exit or detour. A sound signal arrangement can be included in combination with the signal lights.
The circuit networks for operating the height sensing device and the detour signal device communicate with each other and derive their power from the same power source. Power to the detour signal network is fed through a normally closed switch except when the switch is held in an open position. The switch assumes its normally closed position when reception of the light beam by the light sensing device is interrupted by a vehicle exceeding the predetermined height. A timing device included with the switch maintains the switch in its closed position for a predetermined time to provide a detour signal having a desired time duration. Subsequent reception of the light beam by the light sensing device causes the switch to open and terminate actuation of the detour signal device.
The height sensing device and detour signal device are spaced apart a distance that is compatible with the general speed of traffic on the roadway. This spacing ensures that a vehicle having excess height is given ample opportunity to be alerted by the detour signal device when the vehicle has interrupted the light beam. A roadway exit provided in the vicinity of the detour signal device leads the alerted vehicle to an alternate route such as a depressed service road providing adequate clearance between the vehicle and the overpass, or to any other suitable detour.
The invention accordingly comprises the constructions hereinafter described, the scope of the invention being indicated in the following claims.
In the accompanying drawings, in which several of various possible embodiments of the invention are illustrated,
FIG. 1 is a side view of a roadway detour system incorporating one embodiment of the present invention;
FIG. 2 is a plan view thereof;
FIG. 3 is a simplified schematic block diagram of the roadway detour system operating circuit; and
FIG. 4 is a simplified schematic block diagram showing another embodiment of my invention.
Corresponding reference characters indicate corresponding parts throughout the several views of the drawings.
Referring to the drawings, a roadway detour system 10 incorporates one embodiment of the present inven tion. Detour system 10 includes a height sensing device 12 comprising any suitable known upright standard members such as poles 14 and 16 spaced from each other on small islands 18 and 20 located at opposite sides of a roadway 22. Poles l4 and 16 include any suitable known means 24 for raising or lowering the pole height.
The upper end portion of pole 14 includes any suitable known light beam transmitter 26 for transmitting a collimated beam of light 28 across roadway 22 at a desired predetermined height above roadway 22 which height is generally designated 29. Height 29 of light beam 28 is preferably slightly less than the height of an overpass 30 extending across roadway 22.
The upper end of pole 16 includes any suitable known light receiving means such as a photocell 32. The beam of light 28 from transmitter 26 is arranged to focus on photocell 32.
Detour system 10 further includes a detour signal device 34 comprising any suitable known upright standard members such as poles 36 and 38 spaced from each other on small islands 40 and 42 located at opposite sides of roadway 22. A cross member 44 extending across roadway 22 is supported at the upper portions of poles 36 and 38. Poles 36 and 38 include any suitable known means 46 for raising or lowering the pole height, and the height of cross member 44 over roadway 22 can be arranged to exceed the known maximum height of vehicles in current use.
Detour signal device 34 is located a predetermined distance from height sensing device 12 based on the speed range and maximum stopping distances of traffic on roadway 22. Any suitable known detour signal lights 48 are provided on cross member 44 and any suitable known sound signal device 50 is likewise provided on member 44. Detour signal lights 48 can be of those colors conventionally used to slow down and/or stop traffic.
The operating circuit for detour system comprises any suitable known power source 52 connected to any suitable known normally closed switch 54. Switch 54 is connected to any suitable known timing device 56 for maintaining switch 54 in a closed position. Switch 54 shown in open position in FIG. 3, leads to sound signal 50 and detour signal lights 48. Power source 52 is also connected to transmitter 26 but there is no electrical connection between transmitter 26 and photocell 32. Photocell 32 is connected to any suitable known amplifier 58 which amplifier electrically communicates with any suitable known switch control means 60 for maintaining switch 54 in an open position.
In use, roadway detour system 10 transmits light beam 28 from transmitter 26 to photocell 32. Photocell 32 is arranged in any suitable known manner to convert light beam 28 to an electrical signal. Amplifier 58 is arranged in any suitable known manner to amplify the electrical signal from photocell 32. The amplified electrical signal from amplifier 58 activates switch control means 60 to maintain switch S4 in an open condition. Consequently, there is an open circuit between power source 52 and signal devices 48,50 when light beam 28 is transmitted to photocell 32.
Reception of light beam 28 by photocell 32 can be interrupted by a truck 62 that passes between poles 14,16 and exceeds predetermined height 29 of beam 28. Photocell 32 is thus prevented from producing an electrical signal thereby deactivating switch control means 60. As a result, switch 54 assumes its normally closed position permitting power to flow from source 52 to detour signal lights 48 and sound signal 50. Timer 56 is arranged in any suitable known manner to be activated when switch 54 closes.
Timer 56 serves to maintain switch 54 in its normally closed position for a predetermined time duration after photocell 32 begins to again receive light beam 28 from transmitter 26. Detour signal lights 48 and sound signal 50 are thus activated for the predetermined time it would normally take to detour a vehicle that has actuated detour signal 34.
Detour signal lights 48 can be shaped as arrows that point to a roadway exit or detour 64 provided near detour signal device 34. If desired, detour signal device 34 can also carry an illuminated message giving detour directions. Detour 64 leads vehicle 62 away from overpass 30 to a depressed service road (not shown) that provides sufficient clearance between vehicle 62 and overpass 30, or detour 64 can lead to any other suitable alternate route.
As will be apparent to those skilled in the art, height sensing device 12 and detour signal device 34 can be supported or suspended from any other suitable known support means besides poles. It will also be apparent that transmitter 26 can be arranged to transmit two collimated light beams spaced apart a predetermined distance such as shown at 28 and 66 in FIG. 3.
Provision of light beam 66 in addition to light beam 28 can help guard against nonvehicular actuation of detour signal 34 as by a leaf or any other randomly moving object that,might cross the path of a light beam. The spacing between beams 28 and 66 can be arranged to ensure that at least one light beam is received by photocell 32 in the event of an undesired interruption of the other light beam.
Since more than one vehicle may be alerted or stopped by roadway detour system 10, detour signal device 34 can be arranged to carry a concise illuminated or recorded message such as DANGER! Overpass Ahead. Vehicles Exceeding 18 Feet Must Exit." Any other known visually attractive means for directing an endangered vehicle off the roadway can be simultaneously actuated in a known or previously described manner for operation in combination with detour signal device 34.
Detour system 10 can be functionally arranged to extend across more than one lane or roadway including lanes in which traffic moves in opposite directions. For example, the height sensing device for detour system 10 can include a plurality of spaced light beam transmitters 68, 70 and 72 identical to transmitter 26, as shown in FIG. 4. Transmitters 68, 70 and 72 transmit light beams 74, 76 and 78 to photocells 80, 82 and 84 identical to photocell 32. The operating circuit for this modified roadway detour system can be arranged in any suitable known manner to activate detour signal device 34 only when light beams 74, 76 and 78 are interrupted in a predetermined sequence such as 74-7- 6-78.
In FIG. 4, traffic moving in one direction is symbolically indicated by arrow 86 and traffic moving in the opposite direction is symbolically designated 88. An oversize vehicle moving in direction 86 will interrupt the light beams in sequence 74-76-78 and thereby activate detour signal device 34. Conversely, an oversize vehicle traveling in direction 88 will interrupt the light beams in the sequence 78-76-74 thereby having no effect on detour signal device 34.
Some advantages of the novel invention evident from the foregoing description include a roadway detour system that detours vehicles exceeding a predetermined height to a roadway exit, a roadway detour system having a detour signal device that can be actuated into operation by a vehicle passing a check point in a given direction, and a roadway detour system that does not require installation of special equipment on those vehicles which the detour system is designed to protect.
In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained.
As various changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense,
What is claimed is:
l. A roadway detour system for vehicles comprising means for sensing the height of vehicles in combination with means for providing a detour signal, said height sensing means including means for transmitting a light beam at a predetermined height across said roadway, and light sensing means for receiving the beam of light crossing said roadway, said light sensing means including a collimating member for collimating said light beam, said detour signal means being connected to and operable by said height sensing means and comprising a signal device located between said height sensing means and a roadway exit, and normally inactivated when said light beam is received by said light sensing means, said roadway detour system further including means for activating said signal device to produce said detour signal when reception of said light beam by said light sensing means is interrupted by a vehicle having a height in excess of said predetermined height.
2. A roadway detour system as claimed in claim 1 further including an electric power supply means and wherein said detour signal device is electrically operable, said means for activating said detour signal device including switch means interposed between said power supply means and said detour signal device, said switch means being in a first switch position wherein said power supply means is isolated from said detour signal device when said light beam is received by said light sensing means, and said switch means being in a second switch position wherein said power source is electrically communicative with said detour signal device through said switch means when reception of said light beam by said light sensing means is interrupted.
3. A roadway detour system as claimed in claim 2 wherein said switch means has an open position, and a normally closed position, said first switch position being the open position wherein said switch means opens the circuit between said power supply means and said detour signal device, said second switch position being the normally closed position wherein said power supply means communicates with said detour signal device through said switch means.
4. A roadway detour system as claimed in claim 3 fu rther including a timing device connected to said switch means for maintaining said switch means in said closed position for a predetermined amount of time when reception of said light beam by said light sensing means is interrupted.
5. A roadway detour system as claimed in claim 1 wherein said detour signal device produces a visual signal.
6. A roadway detour system as claimed in claim 5 wherein said detour signal device further produces a sound signal.
7. A roadway detour system as claimed in claim I wherein said height sensing means is spaced a predetermined distance from said detour signal means such that said vehicle when moving in a given direction approaches said detour signal means after passing said height sensing means.
8. A roadway detour system as claimed in claim 1 wherein said light transmitting means are provided in a first upright member disposed at one side of said roadway, said light receiving means being provided in a second upright member disposed at a second side of said roadway opposite the first side of said roadway.
9. A roadway detour system as claimed in claim 1 wherein said height sensing means includes means for varying the height of said light transmitting means and said light sensing means.