Public transit vehicle arrival information system

A system for notifying passengers waiting for public transit vehicles of the status of the vehicles, including the arrival times of vehicles at stops. The system includes global position determining devices located in the vehicles for determining the location of the vehicles along their routes. A central processor or computer is coupled to the global position determining devices for receiving the locations of vehicles therefrom. The processor is programmed to compute and update from the present location of the transit system vehicles and electronically stored information a transit data table which includes status information for all the vehicles in the system, including the location of scheduled stops, connections to other transit vehicles at the stops, and the arrival times of vehicles at their stops. The vehicle status and other information, including news and advertisements are then made available for public access in a manner geared to the locations of the vehicles, the time of day, day of week, date, location, season, holiday, weather etc. Portable access means such as pagers, notebook and palm computers and telephones and stationary access means such as personal computers and telephones and display modules in communication with the central processor, receive the computed arrival time and other information for selected routes, stops, etc. from the central processor, and communicate the information to the passenger(s).

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S) Turning now to the drawings, where like components are designated by like reference numerals, FIG. 1 schematically illustrates one preferred embodiment 10 of a transit vehicle arrival notification system in accordance with the present invention. Here, a vehicle 12 has located therein a global positioning system device 14 which includes or is connected to a microprocessor 16 . Global positioning system 14 device is in communication with a plurality of orbiting satellites 18 , such as those associated with the satellite navigational system maintained by the US government, via vehicle antenna 19 , and can determine the location of the bus at any time from the satellite feed. The vehicle 12 can be any of a number of different types of vehicles, including buses, vans, etc., which operate on road surfaces such as surface streets and highways; buses, trolleys, trains, etc. which ride along rails, such as the rails 13 shown in phantom in FIG. 1 ; watercraft such as passenger boats or ferries; and aircraft such as airplanes and helicopters. For convenience and to emphasize the breadth of the invention, we refer to vehicle 12 as both a vehicle and a bus. Please note, typically vehicle 12 is one of several such vehicles deployed by a transit vehicle operating company to operate over one or more routes in a given area. Each of the routes travelled by a particular vehicle typically is identified by a route number or letter. Vehicle 12 is scheduled to stop at one or more public transit stops 20 located on its route between a starting point and a destination point. Microprocessor 16 is in wireless communication with a central processor system 22 , for example, via a communications link such as wireless radio link established between antenna 19 of vehicle 12 and antenna 23 associated with central processor system 22 . Central processor 22 may be operated by the transit vehicle operating company, and be in communication via one or more antennae such as 23 with some or all of the buses operated by that company. Alternatively, central processor 22 may be operated by a municipality or a service bureau and be in communication with buses operated by two or more transit companies. Central processor 22 is in communication with electronic storage means 24 . In electronic storage means 24 are stored the identification of all vehicles or buses in communication with central processor 22 and the location coordinates representing the routes of all vehicles in communication with central processor 22 . Also stored are location coordinates of transit stops 20 along each of the routes and “normal” transit times for a bus between each of the stops. Preferably, the transit data table contains schedules or tables which list (1) each run of a transit vehicle for a given time period, such as a day, and associated schedule information including (2) the predicted time intervals between adjacent transit stops, (3) the associated predicted time of arrival at each stop for each run, and (4) the predicted change in historical passenger load at each stop. The predicted time intervals, arrival times and passenger loads are calculated based upon the history of these items, taking into account the month, week, day, time-of-day, etc., as well as other historical factors or patterns including weather, holidays, vacation seasons, school year holidays, etc. Also, information regarding current conditions or status can be input to the central processor means, either locally (at the central processor means itself) or remotely (for example, from transit vehicles, transit line booths, etc.), and used for revising the predicted time intervals, times of arrival and passenger loads for upcoming stops in the transit data table. Current information includes severe weather, transit line or local surface road construction, and other construction activity, etc. After updating the transit data table to reflect current information, the central processor means controls the broadcast of the revised schedule information throughout the area encompassing the transit system. The process of updating and broadcasting is done as quickly as technology allows, perhaps in a minute or less using present technology. In this way, continually updated near real time system information is available for all who provide, use, or relate to, the transit system. In one aspect of the present invention, each vehicle automatically reports to the central processor 22 or, preferably, central processor 22 is programmed to communicate with (poll) each vehicle 12 which is currently “in-transit” to determine a location of the bus. This communication may be at some convenient short time-interval such as thirty seconds or one minute. Such a time-interval should be, for practical reasons, shorter than the shortest anticipated transit time between any two sequential stops. Locations of the in-transit buses determined from the communication are stored in electronic storage means 24 and updated after each communication. A master clock 26 , connected to or incorporated in central computer 22 , assigns a time-of-day to the system. The distance between any two sequential stops may be computed by central processor or computer 22 from the location of the stops and the route details. Alternatively, distances between sequential stops may be stored in a table or tables in storage means 24 and simply “looked-up” by processor 22 . The tables store normal times as defined above for every operating vehicle in the system. Also, the tables hold schedules for buses entering the system. From the distance and location information, the central computer calculates predicted arrival times at every vehicle stop on the route designated for a vehicle (and preferably uses the capabilities described subsequently to calculate a predicted passenger load). The computer predicts arrival times and passenger loads with increasing accuracy based upon the expanding data base covering vehicles travelling on the particular route under similar operating conditions at similar times of the day, week and month, and schedules. Such predictions can be checked against mathematical formulae to assure reasonableness, and to identify vehicle operational problems. Each calculation can be updated regularly as new information is received from transit vehicles, and quickly. The update process for an entire transit system may only take seconds. Thus the system could be updated with actual system performance information in real time. The most recent calculations can be held in tables such as a “Current transit data table of Predicted Arrival Times and Passenger Loads” or “Transit Data Table”, together with important operation information, for immediate use in supplying information to display units at transit stops and other locations. At transit stop 20 are means for accessing the transit data table and other system information, illustratively in the form of one or more display modules 30 . Display module 30 includes a display device 32 , such as a liquid crystal display, a CRT (cathode ray tube) display and/or an LED (light emitting diode) display, for displaying information. Interactive display modules can be used which include, for example, a data input device 34 , such as a set of switches, buttons, or a keypad. The display module(s) could also be mounted in locations such as office lobbies, stores, restaurants, museums, and other places where people gather. Display module 30 is in communication with central processor 22 , for example, via a link 36 such as a wireless telephone link or a hardwired link. The display modules 30 may be little more than alphanumeric digital pagers of the type regularly available to consumers, or pagers modified with larger screens 32 . These units can be powered from electrical service at the stop, or to save installation costs, and where practical, solar power with battery back-up can be used. These devices may receive the entire transit data table information or a subset thereof. Alternatively, the display modules can be small computers capable of receiving the entire transit data table or a subset thereof and other messages, and capable of being programmed locally, or from the central computer, to format and display those the relevant transit data table and informational messages. In another alternative arrangement, the display modules or units 30 receive the entire transit data table or a subset of the transit data table as well as programming instructions from the central computer so that the content of any particular display can be controlled from the central office. The displays also can display varying levels of graphics and text, allowing the display of messages of public interest and advertising interspersed with transit data table. Each display can be separately addressable, so only messages important to one area may be directed only to that area. The displays such as 30 can transmit the accessed information in audio or visual or audiovisual format. In addition, and referring to FIG. 1 , the access means can be a telephone 25 which communicates with the central processor or computer 22 via a telephone exchange 27 or cellular installation, for transmitting in audio or audiovisual format the information which is broadcast electronically over the system under control of the computer. A server or other suitable device is used to store transit data table information and provide access from telephone(s). Persons of ordinary skill can devise methods of protecting these devices from vandalism. Such devices may also include systems for audible reporting to the visually impaired. Referring to FIGS. 1 and 6 , access means, here one or more display modules designated 30 P to indicate their location in vehicles for serving passengers, can be mounted at convenient and visible locations in transit vehicles. Such displays 30 P can then display upcoming vehicle stops, important points of interest, connecting transit lines, destinations, destination arrival times, the arrival times of connecting vehicles, route change information, public interest and advertising messages, etc. Alternatively, one or more access means such as displays 30 D can be used to provide information that is intended primarily or solely for the driver or operator of the vehicle. In addition to the information available at the passenger displays, such driver-specific information access means can be used to display safety and status information and instructions such as information regarding the time and distance to the next stop(s), instructions to speed up to a certain speed or slow to a certain speed, instructions to bypass the next stop or stops, etc. The driver information displays can be, for example, a separate display or a part of the display in the driver's compartment. In one specific operating mode of system 10 , a passenger waiting at stop 20 or at another location which displays information about lines which serve stop 20 , enters a desired route number (or an alphanumeric code representing that route number) into a display module such as 30 . The display module processes the entered route number, and a code identifying stop 20 , and determines from the transit data table data received from central processor 22 , information such as the predicted arrival time at stop 20 , which is then retrieved and shown on a display module such as 30 . It will be evident to one familiar with the art to which the present invention pertains that central processor 22 may be programmed to provide not only information regarding the next bus of a particular route number to arrive at stop 20 , but may also be programmed to provide more comprehensive information such as arrival times of the next two or more buses of a particular route number or the arrival times of the next one or more buses of all route numbers which are scheduled to stop at stop 20 . Clearly, the more comprehensive the information, the more complex must be the display modules such as 30 , 30 D, 30 P and 31 . Information from the system should be of great use to the transit operator in managing the system as well. The computer can determine the most efficient allocation of vehicles to meet passenger loads, and can schedule turn backs and other adjustments of operating schedules in order to eliminate “bunching” of transit vehicles. The sight of a bus speeding by a passenger in order to re-space vehicles will be far less annoying to the passenger if the display unit informs the passenger of what is happening, and also informs the passenger that a bus is following directly behind. As noted above, in addition to knowledge of a bus's arrival time being useful for a waiting passenger, knowledge of availability of seating on an arriving bus may be equally important. Because of this, it is preferable that bus 12 include an arrangement for determining the passenger load of the bus. This information may be communicated to central processor 22 , together with the location of bus 12 , and stored in storage means 24 . A history of changes in passenger load can then be calculated and stored in storage means 24 using actual passenger load information and historical changes in passenger load between stops for similar times of day, seasons, etc. Based upon this information, predictions for passenger load at upcoming stops can be calculated. Thus the arrival time of, and the available seats and/or standing room on bus 12 can be communicated to the display module for display thereon. It is preferable that the passenger-occupation-load-determining arrangement 40 function automatically, i.e., it is preferably not dependent on a driver of the bus for updating as passengers alight and board at each stop. In a relatively simple form, such an automatic seat availability determining arrangement may be a device for estimating the instant weight of bus 12 , for example a deflection sensor or strain gauge mounted on a wheel suspension component of the bus. Microprocessor 16 may be programmed to estimate passenger load from a signal from the deflection sensor representative of the weight of bus 12 ; the empty weight of the bus; and a predetermined “average” passenger weight. Such a simple device however can at best provide only an estimate of the number of unoccupied seats. Accuracy of the estimate will be influenced, in addition to differences between actual and average passenger weights, by factors such as vibration and fluctuating fuel load in bus 12 . Referring now to FIGS. 2 and 3 , there is shown another arrangement for determining seat availability is illustrated. Here, bus 12 has a forward door 42 through which passengers board the bus, and a mid-point door 44 through which passengers alight from the bus (see FIG. 2 ). Located proximate opposite posts of door 42 is an optical transmitter 46 , such as a light-emitting diode (LED), and a detector or receiver 48 for receiving a light beam (indicated by broken line 50 ) from transmitter 46 . Receiver 48 is connected to microprocessor 16 as illustrated in FIG. 3 . When beam 50 is broken by a passenger boarding through door 42 , receiver 48 transmits a pulse to microprocessor 16 indicating that the passenger has boarded. Similarly, a light source 46 and a receiver 52 (also connected to microprocessor 16 ) are located at door 44 for counting passengers alighting from the bus. The difference between the number of passengers boarding and alighting and the total number of seats in the bus are used by microprocessor 16 to compute the number of unoccupied seats. That number is communicated to central processor 22 on demand. Please note, accurate passenger load monitoring using this arrangement is dependent upon the passengers entering and exiting via designated doors. Such ideal behavior may not prevail, particularly when accurate calculation is most needed, for example during rush hour. In another seat counting arrangement 40 , depicted in FIGS. 4 and 5 , each seat 54 in bus 12 has attached thereto a pressure sensitive switch or bi-modal deflection sensor 56 (see FIG. 4 ). Switch 56 is set to activate (turn “on”) when a passenger sits on the seat, and deactivate (turn “off”) when the passenger leaves the seat. The plurality of switches 56 is connected to microprocessor 16 (see FIG. 5 ). A polling communication from central processor 22 polls global positioning system 14 via microprocessor 16 to determine the location of bus 12 , and also polls switches 56 via microprocessor 16 to determine how many switches are off, i.e., how many seats 54 are unoccupied. Continuing now with reference to FIG. 6 , in another embodiment 11 of a transit vehicle arrival notification system in accordance with the present invention, bus 12 (being one of a plurality of such buses) is provided with electronic storage means 17 in which data including the route of the bus and stop locations along that route are stored. (For simplicity, elements and systems such as displays 30 P and 30 D and telephone means 25 and 27 are not shown in FIG. 6 , but it is understood such elements and systems are applicable to system 11 , as well as to system 10 , FIG. 1 ). Microprocessor 16 is programmed to compute from location data obtained from global positioning system device 14 , and from the data stored in storage means 17 the anticipated arrival time of the bus at stops to be encountered along its route. This may be done, as discussed above, at regular, relatively short time-intervals. When bus 12 of system 11 is polled by central processor 22 , the computed arrival times and instant seat availability are transmitted to the central processor and stored in electronic storage means 24 attached thereto. In system 11 there is no requirement for storage 24 to store any route or stop location details. When central processor 22 is queried by display module such as 30 , central processor 22 looks up the requested arrival times and capacity in storage 24 and transmits them to the module for display. A particular advantage of either system 10 or system 11 is that a display module such as 30 for presenting arrival and seat availability information can receive wireless communications from central processor or computer 22 . As the display modules such as 30 need receive only a short text message from processor 22 for display, the module can be made quite small and would require very little power to operate. Display module 30 at stop 20 for example could be easily powered by a small solar power generating unit of a type now used in many states on roadside emergency telephones. A passenger 60 may also carry a portable display module 31 (shown exaggerated in size in FIGS. 1 and 6 ). Display module 31 could receive via a dedicated wireless telephone link (indicated by broken line 62 ) information from or selected by central processor 22 . Module 31 , in practice, need be no bigger or heavier, or cost no more than a small paging unit of a type which is now commonly used by many persons to receive text messages from a central office. T h e portable display modules 31 , can be used to receive the transit data table, and access arrival information for any particular transit line and transit stop. In this way a person can know, without leaving home, work, a restaurant, etc., precisely when the next vehicle will arrive. The device will have the ability to also display all of the transit data table by scrolling through all data items or, on more sophisticated display devices, by direct access. The system will include programs for personal computers, palm top computers, electronic organizers and/or dedicated devices capable of determining the fastest means to reach any particular destination by analyzing various transit alternatives based upon user input parameters such as the number of blocks a passenger is willing to walk from the area of origination to the area of destination. Such analyses will be based upon real time transit operation information. Devices will include a priority display to make access of information for designated stops easy. A portable display module 31 would be extremely useful for a business person or any person who commutes by bus. By way of example, the person may inquire into the arrival time and seat availability of buses before leaving the work-place. If it were found that a bus would arrive late or not have an available seat at the business person's usual transit stop, the business person need not venture to the transit stop, and could spend time, which would otherwise be spent waiting in line, gainfully, at work or shopping. In summary, a public transit vehicle arrival notification system has been described. The system is for notifying a passenger waiting for a public transportation vehicle of the arrival time of the vehicle at a transportation stop. The vehicle may be one of a plurality of buses travelling one of a plurality of predetermined routes. The stop may be any one of a plurality of stops along a particular one of the routes. Details of the arrival time of the bus at the stop and details of seat availability on the bus are transmitted to a central computer. A significant advantage of the system is that a waiting passenger may use a portable module to establish wireless communication with the central computer from any location within the operating range of the system. The central computer transmits the arrival time and seat availability to the module for display. The passenger has available at transit stops and other locations display module 30 and 30 P and may carry on his or her person a portable display module 31 , any or all of which provide news and weather information, announcements, advertising, etc., as well as a continuously updated electronic timetable which provides, in addition to bus arrival times, information regarding seating availability on arriving buses. The advertising capability of the system provides needed revenue. Revenues to fund the system can come from the various transit agencies and government entities. However, revenues to support the system and to service the investment necessary to create the system can be obtained by selling advertising time associated with the display panels. Such advertising can be of general area wide interest, or more interestingly, can be quite site specific. For instance, it would be possible to advertise to a bus stop in front of an ice cream shop, “The next bus is ten minutes away, how about a scoop of pralines and cream&quest;” and another message to another bus stop. Such advertising might be a real boon to neighborhood business. Such advertising may also be timed to only appear at certain stops, times of day, days of week, special holidays, or a variety of other particular considerations of time, weather, location, and transit system movement. Moreover, advertising messages may be timed with relation to the approach of the transit vehicle. For example, a message advertising the ice cream shop might be sent ten minutes before the bus arrival, because the customer would have time to react, while national advertisements would show in the minute before the bus arrived to assure the greatest audience. The advertising could also be related to weather or other timely considerations, for example advertising umbrellas in the store behind the bus stop during a rain storm. Similarly, advertising messages can appear in transit vehicles that are relevant to the location of the transit vehicle and the time of day. Consider the power of the message “Roses $4.95 a dozen, next stop, next bus ten minutes behind” for the flower retailer and for romance in general&excl; The system could also send out messages of general interest over wide geographic areas, including Silent Radio. Advertising opportunities on the cases of public display units can also be licensed for revenue. Since all transit riders are likely to regularly observe such displays, and since advertising can be made so site specific, advertising as a part of this system should be of significant value and affordable to a variety of national, local and neighborhood businesses. The present invention has been described and depicted in terms of a preferred and other embodiments. The invention, however, is not limited by the embodiments described and depicted. Rather, the invention is limited only by the claims attached hereto.