Patent Publication Number: US-RE46727-E

Title: Taxi trip meter system with indication of fare and distance violations

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This is a reissue of U.S. Pat. No. 6,122,591, which was issued on Sep. 19, 2000. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates generally to taximeters. 
     2. Prior Art 
     A taxi fare is typically determined by a taximeter based on trip distance and waiting time in traffic. Taxi drivers are free to take whichever route they choose. Riders who are unfamiliar with the area being traversed are sometimes cheated by unscrupulous taxi drivers who take a roundabout route to inflate the fare. Other taxi drivers try to increase income by driving very fast to minimize travel time and thus increasing customer turnover, but at the expense of safety. 
     OBJECTS OF THE INVENTION 
     Accordingly, objects of the present taxi trip meter system are:
         to provide an estimated shortest trip distance for an estimated best route;   to indicate a violation if the estimated shortest trip distance is exceeded by an actual trip distance by a permissible margin;   to calculate an actual average speed for the trip;   to indicate a violation if an estimated average speed limit for an actual travel route is exceeded by the actual average speed;   to provide an estimated taxi fare based on the estimated shortest trip distance and an estimated waiting time in traffic; and   to indicate a violation if the estimated taxi fare is exceeded by an actual taxi fare by a permissible margin.       

     Further objects of the present invention will become apparent from a consideration of the drawings and ensuing description. 
     BRIEF SUMMARY OF THE INVENTION 
     A taxi trip meter system includes a taximeter and a location sensor connected to a computer loaded with street information and driver evaluation software. In a first embodiment, the estimated shortest route and distance between the starting and ending points of a trip are determined. If the estimated shortest trip distance is exceeded by an actual trip distance by a permissible margin, a distance violation is indicated. An actual average speed is calculated based on an actual trip duration and the actually traveled distance. If an estimated average speed limit for the actual route is exceeded by the actual average speed, a speed violation is indicated. In a second embodiment, an estimated taxi fare is calculated based on the estimated shortest route. If the estimated taxi fare is exceeded by an actual taxi fare calculated by the taximeter by a permissible margin, a fare violation is indicated. 
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
       FIG. 1  is a block diagram of the present taxi trip meter system. 
       FIG. 2  is a flowchart for a first embodiment of a method implemented by the taxi trip meter system. 
       FIG. 3  is a flowchart for a second embodiment of the method implemented by the taxi trip meter system. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1 : A first embodiment of the present taxi trip meter system is shown in  FIG. 1 . It is mounted in a vehicle, e.g., a taxi, and includes a computer  10  receiving taxi fare information from a taximeter  11 , trip distance information from a trip meter  12 , and geographical location information from a location sensor  13 . Taximeter  11  also receives input from trip meter  12 . Computer  10  may be any type of programmable processor, and is preferably loaded with detailed street and highway information, e.g., from a CD-ROM street navigation program. Location sensor  13  may be any type of device that indicates the precise geographical location of the vehicle, such as a GPS (global positioning satellite) receiver. A radio transmitter  14 , a display  15 , and a printer  16  connected to computer  10  enable the output of driver evaluation information in different forms. 
       FIG. 2 : A first embodiment of a taxi trip meter method implement by the system of  FIG. 1  is shown in  FIG. 2 . It is preferably implemented as software or firmware in the computer. The process is started at block  20 . When a trip is begun at block  21 , e.g., when the taximeter is activated or a specific initiating input is provided to the computer, the geographical starting point is determined at block  22 , and the starting time is marked at block  23 . A recording of the actual route being traveled is begun at block  24 . When the vehicle has reached its destination and the trip is ended at block  25 , e.g. when the taximeter is deactivated or a specific terminating input is provided to the computer, the geographical destination point is determined at block  26 , and the ending time is marked at block  27 . The starting and ending points are determined with the location sensor and the street information loaded in the computer. The recording of the actual route is stopped at block  28 . The actual trip distance is determined at block  29  with input from the trip meter or with street information. The actual trip duration is determined at block  30  by calculating the difference between the starting and ending times. Alternatively, a timer may be employed. 
     Based on available street information, the optimal route and shortest trip distance between the starting and ending points are estimated at block  31  with any suitable method well known in the art. The shortest trip distance is preferably determined for an actual street route, but if the computer is not provided with street information, the straight-line distance between the starting and end points may be considered as the estimated shortest trip distance. A permissible margin over the estimated shortest trip distance is determined at block  32 . The margin may be a fixed percentage over the estimated shortest distance, or it may be a variable percentage that is greater for shorter distances, or smaller for longer distances. 
     The actual trip distance is compared to the estimated shortest trip distance at block  33 . If the estimated shortest trip distance is exceeded by the actual trip distance by the permissible margin, a distance violation is indicated at block  34 . The indication for the violation may be provided in various forms, e.g., as a transmission to the taxi company headquarters through the transmitter, as information on the display, or as a printout from the printer. The taxi customer and the taxi company are thus notified of an excessively long route taken by the taxi driver. A powerful deterrent is thus provided against cheating by the taxi driver. 
     A further feature is provided for monitoring driving speed. The average actual speed for the trip is calculated at block  35  based on the actual trip distance and trip duration. If an estimated average speed limit for the actual route, which may be provided as part of the street information, is exceeded by the average actual speed at block  36 , a speed violation is indicated at block  37 . The process is ended at block  38 . A powerful deterrent is thus provided against speeding by the taxi driver. 
       FIG. 3 : A second embodiment of the taxi trip meter method implement by the system of  FIG. 1  is shown in  FIG. 3 . It is preferably implemented as software or firmware in the computer. The process is started at block  40 . When a trip is begun at block  41 , e.g., when the taximeter is activated or a specific initiating input is provided to the computer, the geographic starting point is determined at block  42 , and the starting time is marked at block  43 . A recording of the actual route being traveled is begun at block  44 . When the vehicle has reached the destination point and the trip is ended at block  45 , e.g. when the taximeter is deactivated or a specific terminating input is provided to the computer, the geographic destination point is determined at block  46 , and the ending time is marked at block  47 . The starting and ending points are determined with the location sensor and the street information loaded in the computer. The recording of the actual route is stopped at block  48 . The trip duration is determined at block  49  by calculating the difference between the starting and ending times. Alternatively, a timer may be employed. 
     Based on available street information, the optimal route and shortest trip distance between the starting and ending points are estimated at block  50  with any suitable method well known in the art. The shortest trip distance is preferably determined for an actual street route, but if the computer is not provided with street information, the straight-line distance between the starting and end points may be considered as the estimated shortest trip distance. An estimated waiting time in traffic along the optimal route is determined at block  51  based on location traffic information and the time of day to account for traffic lights, traffic congestion, etc. An estimated fare is determined at block  52  based on the estimated shortest trip distance and estimated waiting time, and displayed at block  53 . A permissible margin over the estimated fare is determined at block  54 . The margin may be a fixed percentage over the estimated fare, or it may be a variable percentage that is greater for lower fares, or smaller for higher fares. 
     An actual fare computed by the taximeter is compared to the estimated fare at block  55 . If the estimated fare is exceeded by the actual fare by the permissible margin, a fare violation is indicated at block  56 . The indication for the violation may be provided in various forms, e.g., as a transmission to the taxi company headquarters through the transmitter, as information on the display, or as a printout from the printer. The taxi customer and the taxi company are thus notified of an excessive fare charged by the taxi driver. A powerful deterrent is thus provided against cheating by the taxi driver. 
     A further feature is provided for monitoring driving speed. The actual average speed for trip is calculated at block  57  based on the actual trip distance and trip duration. If an estimated average speed limit for the actual route, which may be provided as part of the street information, is exceeded by the actual average speed at block  58 , a speed violation is indicated at block  59 . The process is ended at block  60 . A powerful deterrent is thus provided against speeding by the taxi driver. 
     SUMMARY AND SCOPE 
     Accordingly, a taxi trip meter system is provided. It provides an estimated shortest trip distance. It indicates a distance violation if the estimated shortest trip distance is exceeded by an actual trip distance by a permissible margin. It calculates an actual average speed for the trip. It indicates a speed violation if an estimated average speed limit for the actual route is exceeded by the actual average speed. It provides an estimated fare based on the estimated shortest trip distance and an estimated waiting time. It indicates a fare violation if the estimated fare is exceeded by an actual fare by a permissible margin. 
     Although the above description is specific, it should not be considered as a limitation on the scope of the invention, but only as an example of the preferred embodiment. Many substitutes and variations are possible within the teachings of the invention. For example, the starting and ending points may be inputted before the trip to provide advance notice of the fare. The estimated fare based on the optimal route may be used as the actual fare to completely eliminate the possibility of cheating. The trip meter may be eliminated, and the trip distance may be determined with GPS and map data. When a violation is indicated, the recorded route may be reviewed by the taxi company or government authority for excusable causes, such as accidents, parades, road closures, etc. A printed ticket may be provided for the customer for subsequent resolution with the taxi company. The fares calculated by the taximeter and the taxi trip meter system may be considered as including distance information. The trip meter may be indirectly connected to the computer through the taximeter. Therefore, the scope of the invention should be determined by the appended claims and their legal equivalents, not by the examples given.