U.S. patent number RE38,724 [Application Number 09/721,608] was granted by the patent office on 2005-04-12 for method and apparatus for providing shortest elapsed time route and tracking information to users.
Invention is credited to Thomas D. Peterson.
United States Patent |
RE38,724 |
Peterson |
April 12, 2005 |
Method and apparatus for providing shortest elapsed time route and
tracking information to users
Abstract
A method and apparatus for determining and communicating
shortest elapsed time route information to users wherein
information of desired origin and destination combinations is
received from the users in a central processor or computer, instant
rates of travel on multiple route segments interconnecting various
possible origins and destinations being monitored and transferred
to the central processor which then calculates the route segment or
segment combination providing shortest elapsed time routes for each
origin-destination combination and transmitting that information to
the respective user. Communication between the central processor
and the users is preferably by telephone and more preferably by
cellular telephone.
Inventors: |
Peterson; Thomas D. (Sonoma,
CA) |
Family
ID: |
34427012 |
Appl.
No.: |
09/721,608 |
Filed: |
November 21, 2000 |
Related U.S. Patent Documents
|
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
|
436892 |
May 8, 1995 |
5523950 |
|
|
|
032830 |
Mar 10, 1993 |
|
|
|
|
649599 |
Feb 1, 1991 |
|
|
|
Reissue of: |
599309 |
Feb 9, 1996 |
05845227 |
Dec 1, 1998 |
|
|
Current U.S.
Class: |
701/414; 340/905;
340/989; 701/117; 701/423; 701/467 |
Current CPC
Class: |
G01C
21/3461 (20130101); G08G 1/096811 (20130101); G08G
1/096894 (20130101) |
Current International
Class: |
G01C
21/34 (20060101); G08G 1/0968 (20060101); G01C
021/34 () |
Field of
Search: |
;701/117,119,200,202,208,209,210,213
;340/905,988,989,990,993,995 |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
Boyce, David E., "Route Guidance System for Improving Urban Travel
and Location Choices", Journal of Transportation Research, 1998,
pp. 277-281..
|
Primary Examiner: Chin; Gary
Attorney, Agent or Firm: Erickson; Don E
Parent Case Text
This reissued patent is based on U.S. Pat. No. 5,845,227, which is
a continuation-in-part of allowed U.S. patent application Ser. No.
08/436,892, filed May 8, 1995, now U.S. Pat. No. 5,523,950 which is
a continuation of Ser. No. 08/032,830, filed Mar. 10, 1993,
abandoned, which is a continuation of Ser. No. 07/649,599, filed
Feb. 1, 1991, abandoned.
Claims
What is claimed:
1. A method for determining and communicating shortest elapsed time
route information to users, comprising the steps of:
.[.individually.]. .Iadd.receiving .Iaddend.monitor.[.ing.].
.Iadd.ed .Iaddend.instant rates of vehicular travel on multiple
route segments interconnecting various possible origins and
destinations, .[.such monitoring to include the use of.].
.Iadd.where said instant rates of travel are monitored using
.Iaddend.sensing means, .[.differential video imaging means wherein
a fixed video camera measures rates of travel, Global Positioning
System means for measuring movements of a moving vehicle, loop
detectors and tag reading devices for reading the passage of
tag-bearing vehicles.]. .Iadd.the sensing means having the capacity
of identifying the presence of the vehicle at more than one
location.Iaddend.; transferring the monitored instant rates of
travel for the multiple route segments to a processor .[.based on
the tag readings, the Global Positioning System readings and the
loop detector readings which identify the vehicle at more than one
location from which said instant rates of vehicular travel are
calculated.]. ; receiving information of desired origin and
destination in said processor from at least one user.[., including
vehicle type and number of passengers, such that shortest time
route calculation would include all route segments and lanes for
which the vehicle has permission to travel.]. ; calculating the
route segment or combination of route segments based on the
monitored instant rates of travel to provide a shortest elapsed
time route between each origin-destination combination; and
transmitting information of the shortest elapsed time routes for
the origin-destination combination to the .[.respective.]. .Iadd.at
least one .Iaddend.user.
2. A method as set forth in claim 1, .Iadd.wherein the step of
receiving monitored instant rates of vehicular travel on multiple
route segments interconnecting various possible origins and
destinations .Iaddend.includ.[.ing.]. .Iadd.es the additional step
of .Iaddend.monitoring the user's trip progress by .[.Global
Positioning System signal.]. .Iadd.said sensing means .Iaddend.by
recalculating the remaining route continuously using the
then-current sensed information .[.and calling the user if the
directions can be improved.]. .
3. A method as set forth in claim 1, wherein the received
information of desired origin and destination combination includes
an identifier where the .Iadd.at least one .Iaddend.user can be
contacted during the trip.
4. The method of claim 1 wherein the steps of receiving information
of desired origin-destination combinations and transmitting
information of shortest elapsed time routes for the
origin-destination combinations are carried out by .[.means of.].
telephone.
5. The method of claim .[.4.]. .Iadd.1 .Iaddend.wherein the steps
of receiving .Iadd.information of desired origin-destination
combinations .Iaddend.and transmitting information .Iadd.of
shortest elapsed time routes for the origin-destination
combinations .Iaddend.are carried out by .[.means of cellular
telephone.]. .Iadd.a wireless communication device.Iaddend..
6. .[.A.]. .Iadd.The .Iaddend.method .[.as set forth in.]. .Iadd.of
.Iaddend.claim 1, .[.including interaction with a user with.].
.Iadd.wherein the steps of transmitting and receiving with the at
least one user are carried out on .Iaddend.an internet worldwide
network.[., and wherein web sites are used in place of computers
and networks to replace traditional telephone switching systems.].
.
7. The method of claim 1 .Iadd.wherein the step of receiving
information from the at least one user .Iaddend.further
compris.[.ing.]. .Iadd.es .Iaddend..[.of the step of.]. receiving
information .[.from the users includes.]. .Iadd.of .Iaddend.a
contemplated time of departure.
8. The method of claim 1 further comprising the step of collecting
historical real time data in the processor to determine normal time
variations for the instant rates of travel for the multiple route
segments and employing the historical real time data in calculating
the shortest elapsed time route between each origin-destination
combination.
9. The method of claim 8 further comprising the step of receiving
information from the users includes a contemplated time of
departure.
10. The method of claim 1 wherein the step of transmitting
information .Iadd.of the shortest elapsed time routes for the
origin-destination combination .Iaddend.to the .[.respective.].
.Iadd.at least one .Iaddend.user.[.s.]. comprises the transmission
of video data .Iadd.and wherein the shortest elapsed time routes
are displayed on a video receiver.Iaddend..
11. The method of claim 10 further comprising the use of
.[.cellular telephone.]. .Iadd.a wireless communication device
.Iaddend.for transmitting the information of shortest elapsed time
routes for the origin-destination combinations .[.and providing
video receivers for displaying the shortes elapsed time routes to
the respective users.]. .
12. The method of claim 1 .Iadd.the step of calculating the route
segment or combination of route segments .Iaddend.further
compris.[.ing.]. .Iadd.es .Iaddend.the step of storing data for the
shortest elapsed time routes for .[.each respective.]. .Iadd.the at
least one .Iaddend.user for a predetermined time and
.[.transmitting updated information of.]. .Iadd.periodically
recalculating .Iaddend.the shortest elapsed time routes .[.to.].
.Iadd.for .Iaddend.the .[.respective.]. .Iadd.at least one
.Iaddend.user.[.s.]. .
13. The method of claim 1 wherein the step of receiving information
from the .Iadd.at least one .Iaddend.user.[.s.]. includes
.Iadd.receiving information on .Iaddend.multiple destinations, the
shortest elapsed time routes being calculated for the multiple
destinations and transmitted to the .[.respective.]. .Iadd.at least
one .Iaddend.user.[.s.]. .
14. The method of claim 13 further comprising the step of
collecting historical real time data in the processor to determine
normal time variations for the instant rates of travel for the
multiple route segments and employing the historical real time data
in calculating the shortest elapsed time route between each
origin-destination combination.
15. The method of claim 1 further comprising the step of monitoring
instant rates of travel at a plurality of locations along each
route segment in order to provide a more accurate calculation of
the shortest elapsed time routes for the origin-destination
combinations..Iadd.
16. The method of claim 1 wherein the sensing means comprises a
Global Positioning System for measuring movements of the vehicle.
.Iaddend..Iadd.
17. The method of claim 1 wherein the sensing means comprises a
differential video imager that measures rates of travel.
.Iaddend..Iadd.
18. The method of claim 1 wherein the sensing means comprises a tag
reader for reading the passage of a tag-bearing vehicle.
.Iaddend..Iadd.
19. The method of claim 1 wherein the sensing means comprises a
wireless system that measures the change in location of the
vehicle. .Iaddend..Iadd.
20. The method of claim 1 wherein the sensing means comprises a
Radar System for measuring movements of the vehicle.
.Iaddend..Iadd.
21. The method of claim 2 wherein the step of recalculating the
route segment or combination of route segments based on the
monitored instant rates of travel includes the step of
recalculating the remaining route continuously based on the
monitored trip progress. .Iaddend..Iadd.
22. The method of claim 21 wherein the step of transmitting
information of the shortest elapsed time routes includes the step
of transmitting the recalculated shortest route information to the
at least one user. .Iaddend..Iadd.
23. The method of claim 1 wherein the received information includes
the vehicle type and the shortest time route calculation includes
all routes for which the vehicle has permission to travel.
.Iaddend..Iadd.
24. The method of claim 1 wherein the received information includes
the vehicle size such that the shortest time route calculation
includes all routes for which the vehicle has permission to travel.
.Iaddend..Iadd.
25. The method of claim 1 wherein the received information includes
the unique and instantaneous requirements of vehicular lane
restrictions, and the shortest time route calculation includes all
routes for which the vehicle has permission to travel.
.Iaddend..Iadd.
26. The method of claim 1 wherein the received information includes
the number of passengers in the vehicle and the shortest time route
calculation includes all lane segments for which the vehicle has
permission to travel. .Iaddend..Iadd.
27. The method of claim 12 wherein the step of transmitting
information to the user includes transmitting updated information
to the shortest elapsed time routes to the at least one user.
.Iaddend..Iadd.
28. The method of claim 1 wherein the monitored instant rates of
travel is derived from the volume and occupancy data provided by a
single loop sensor. .Iaddend..Iadd.
29. The method of claim 1, wherein the steps of transmitting and
receiving with the at least one user are carried out by satellite
link. .Iaddend..Iadd.
30. The method of claim 1, wherein current vehicle location is
continuously compared with successive waypoints determined by the
shortest elapsed time route calculation. .Iaddend..Iadd.
31. The method of claim 30, wherein the difference between the
actual and expected time at each of the waypoints forms the basis
to inform the at least one user. .Iaddend..Iadd.
32. The method of claim 1, wherein voice recognition is used for
the purpose of the at least one user communicating the desired
origin and destination. .Iaddend.
Description
FIELD OF THE INVENTION
The present invention provides a method and apparatus for supplying
traffic information to users and more particularly to such a method
and apparatus for assisting the users in selecting shortest elapsed
time routes between various origin and destination combinations. In
addition, the invention proves useful for vehicle tracking and
management. The routing is up to the minute, dynamic, constantly
keeping track of the current traffic and recalculating the user's
route considering all changes and calls him back if the route can
be improved.
BACKGROUND OF THE INVENTION
Substantial effort has been exerted in the past and is continuing
to be directed toward solution of the problem directing traffic in
a manner to facilitate travel by individual vehicles between a wide
variety of origin and destination combinations in a minimum amount
of time. This problem is particularly severe in extended urban
areas where individual vehicles commonly travel long distances from
various points of origin to various destinations. Fleet operators
in these environments suffer from not having effective utilization
of their drivers and vehicles.
In most such extended urban areas, there is a wide variety of
routes available to each vehicle. Accordingly, the travel time for
each vehicle could be shortened and traffic control efforts could
generally be much more efficient if individual vehicles could be
supplied with the shortest elapsed time route information for their
respective origins and destinations at the particular travel time
for each vehicle.
Obviously, such information pertains not only to commuters but to
business and recreational travelers at any time as well as service
vehicles such as delivery trucks and the like.
At the same time, such information is particularly desirable in
extended urban areas as noted above. However, it is more broadly
contemplated that such information may be of value in any selected
region, from small to large scale, where there are a variety of
route segments available for traveling between different origin and
destination combinations.
For purposes of the present invention, the San Francisco Bay Area
has been selected as one typical extended urban region wherein such
information and traffic control would be particularly desirable.
However, it is to be noted that the selection of this region is
merely for purposes of example. More broadly, as noted above, the
invention is applicable to any region where there are various route
combinations possible between each origin and destination
combination.
Both commercial and government concerns have been attempting to
develop traffic control systems for alleviating these problems.
However, even where mass transit systems have been effective for
transporting substantial numbers of people, there still remain
large numbers of individual vehicles traveling throughout such
extended areas, both during peak hours and throughout the entire
day.
As noted above, many solutions have been explored or proposed for
providing necessary traffic control in such situations. Possibly
one of the most basic efforts was the supplying of maps, by Rand
McNally Company and others, the maps presenting both distances in
terms of statutory miles and normal travel times in hours and
minutes along large numbers of interconnected route segments. Such
maps were helpful to travelers in selecting a most efficient travel
route. However, that information was generally accurate under
optimum or standard conditions and did not provide any information
to the user concerning instantaneous conditions along different
route segments. U.S. Pat. No. 4,301,506 issued to Turco provided a
computerized system for use in such situations. However, that
patent contemplated an on-board computer or processor for each
individual vehicle for providing alternative route information in
the event of traffic stoppage along any particular route segment.
This solution was relatively complex and expensive and in addition,
generally did not provide assistance until the individual vehicle
encountered an actual condition of traffic stoppage or back-up.
U.S. Pat. No. 4,350,970 issued Sep. 21, 1982 to von Tomkewitsch
provided yet another traffic routing and information system in
which stationary routing status transmission poles were used to
monitor traffic flow and to transmit information concerning traffic
conditions to passing vehicles. However, within this system, it was
necessary for each individual vehicle to have the capability for
transmitting travel time information between the fixed pole
locations along a given route. A central computer or processor was
coupled with the fixed poles to assemble information from the
vehicles and, in turn, to provide information to the vehicles
through the fixed transmission poles regarding conditions to be
encountered by the vehicles.
Here again, however the system was relatively expensive and complex
in terms of the equipment required for the individual vehicles.
More recently, U.S. Pat. No. 4,812,843 issued Mar. 14, 1989 to
Champion, III, et al. provided yet another traffic information
system directly accessible by individual users by means of
telephone, mobile telephone or computer. In this system, a central
computer or processor provided a sorting function of selecting
traffic information specific to a contemplated route for each
individual vehicle and transmitting only the appropriate
information to the respective vehicles.
Here again, although relatively efficient, this system was capable
only of providing information to individual vehicles for
predetermined routes of travel.
The above are only representative of a very wide variety of traffic
control systems adapted for resolving such problems. It is
particularly important to note that, while advancing technology, a
wide variety of means are available both for transmitting necessary
information and for accomplishing necessary monitoring in such
systems. It is particularly to be noted that conventional or
wire-tied telephones have long been available for such purposes.
More recently, mobile or cellular telephones have become
increasingly popular and provide one particular means for supplying
information to individual vehicles. It is also to be noted that
mobile or cellular telephones are merely one form of a wireless
communication link between a central processor or the like and
individual vehicles. Other forms which would perform the function
are two-way radio, paging, text messaging systems, personal
communication services (PCS), fax, satellite link and the like at
any frequency by any means.
In any event, there has been found to remain a need for a more
effective traffic control system for supplying instantaneous route
information to individual vehicles, particularly vehicles faced
with a variety of routes between a given origin and destination
combination. The fleet owner has the same problem in deriving the
benefits of efficient and profitable operation of his fleet.
SUMMARY OF THE INVENTION
It is initially noted that the present invention is concerned with
providing assistance to individual vehicles according to their
unique and instantaneous requirements. Accordingly, traffic control
systems adapted for simultaneously regulating route information for
large numbers of vehicles are outside the scope of the present
invention except as it applies to fleets of vehicles. Fleets are
simply managing many individual vehicles each with its unique
origin, destination, and time of departure.
Rather, it is an object of the present invention to provide
individual vehicles or drivers with desired information in terms of
the shortest elapsed time route between a particular origin and
destination or multiple destinations for a given trip
combination.
More particularly, the invention contemplates a method and
apparatus for simultaneously supplying such information to large
numbers of users having different origin and destination
combinations. Still further, the method and apparatus may be
applied to a specific user area or even to a number of
interconnected or overlapping user areas. In any event, the method
and apparatus of the invention are specific to a given region
including a wide variety of route segments providing different
travel combinations between selected origin and destination
combinations.
Broadly, it is an object of the invention to provide a method and
apparatus wherein instantaneous rates of travel are mounted along
each of the possible route segments in a given region, with that
instantaneous rate information being transferred to a central
processor or computer which is also equipped to receive information
regarding caller's identity (ID), and desired origin-destination
combinations from different users. The central processor then
calculates the route segment or combination of route segments
providing a shortest elapsed time route between each
origin-destination combination and transmits that information to
the respective users. If the user registers his identity in any
other way, for example, phone number, caller ID, (caller ID is now
automatic in some areas) or by internet connection, which transmits
the user's web address (identity), the invention will perform a
number of functions to help them. The computer will automatically
keep track of the user's most frequently requested trips and
present them as choice, i.e., home to work, work to home. The
computer will keep track of the type of vehicle the user is
driving. If the vehicle is a truck, it will indicate what size
truck. If it is an automobile, the computer will determine if there
are sufficient passengers to qualify to use the high occupancy
vehicle (HOV), lanes. Once the vehicle type is determined, the
computer determines which subset of all interconnect arc segments
(the grid) the vehicle has permission to run on, and then
calculates the shortest time route considering only those route
segments the user has permission to use. Permission is generally
set by government authorities and often varies by time of day and
day of week. The computer will automatically keep track of the
user's current location by assuming that the user is on the
shortest time route and that he is travelling at the speed of
traffic predicted for him based on his own individual driving
profile. While the user calls in and enters his caller ID, the
computer will say "Traffic Assist calculates your current position
as . . . " The computer then prompts the user to identify his
actual location in relation to the computer calculated vehicle
position until the computer identifies the user's exact location.
For users equipped with Global Positioning Systems (GPS), the
location of the vehicle will be determined by the computer through
communication with the GPS device in the vehicle. The computer will
monitor the user's progress and upon request will be available to
identify the user's current location and to provide further
directions and the arrival time. It is further the objective to
constantly recalculate the user's route and to call the user back
if conditions change and additional time can be saved. If a change
in route is necessary, the computer will ask the user if he has
passed a particular junction which is the beginning of the new
route. If the user's answer is no, the computer will give the user
his new route to begin at the particular junction.
Preferably, the central processor or computer is also capable of
applying historical data for predicting rates of variation at any
given time and date for each route segment. Accordingly, the method
and apparatus of the invention preferably calculate and transmit to
the users the shortest elapsed time route information for the
actual time when the individual vehicle will be traveling between
its origin-destination combination.
Thus, the present invention provides a method and apparatus for
providing individual vehicles or drivers which necessary
information for determining the most rapid route between a selected
origin-destination combination. The invention relies upon sensors
(sensors would include tag readers and differential video imagery)
or probes (which would include velocities, or changing position
data feed back from vehicles from which elapsed times can be
calculated. Further example is the hand off from cell to cell in a
cellular phone system) along the various route segments in order to
transmit instantaneous rate information for those segments to a
central computer. The central computer receives the information
from all of the sensors and probes along the various route segments
and applies that information to input equations or algorithms for
determining the actual elapsed time, under present conditions,
between points defining each route segment. Typically, those points
are selected as principal arterial highway intersections, nodes and
the like. Algorithms are then applied within the central computer
for comparing actual elapsed times for the various route segments
and aggregating that information in order to determine the shortest
elapsed time route between any point of origin and destination.
As noted above, the central computer is also equipped to
continuously recognize historical rates of change for travel
updated from public and private agencies as well as ongoing rates
from sensors and probes along the various route segments so that
the shortest elapsed time route information can be selected for the
actual times contemplated for travel by the individual vehicle.
Furthermore, the central computer preferably includes means for
storing travel data for each user for a predetermined amount of
time. If communication means is available to the vehicle, for
example by mobile or cellular telephone, updated information can
then be transmitted to the individual vehicle if necessary or
desirable. The route in progress feature allows the driver to
contact by available means, for example, to call to verify his
location and receive directions for the remaining portion of the
trip. Additionally, the computer constantly monitors the route the
driver has been given and recalculates the shortest time route from
his updated origin to determine if his route can be improved. If
conditions change and additional time can be saved, the computer
will make contact, for example, call the driver back and advise the
driver of the new route.
Tracking is an additional feature of the invented system. The
system is predictive as opposed to the other systems which are
reactive. Other tracking systems require the system to be notified
that the vehicle is missing, at which time the system will start to
track the vehicle. In the invented system, when the vehicle starts
to move, the driver is asked to give his destination. The computer
knows his origin because the vehicle has the GPS signal, the means
to determine the GPS change, and communication means. When the
destination is input, the computer calculates the fastest route and
relays it to the driver. Optionally, this trip can be dispatched on
the dispatcher's screen. Simultaneously with giving the driver the
best route, the computer down loads this route, its list of
waypoints and expected time of arrival, based on individual driver
patterns, and the driver's time tolerances. If the vehicle does not
stay on course or on schedule the vehicle and/or the dispatcher can
be called.
Additionally, the logic device associated with the GPS unit which
comprises current vehicle location against waypoints can be set to
act as a precursor to approaching changes in route, or hazards such
as at grade railroad crossings. The driver going west on 80 would
hear a bell or a recording advising of his upcoming turn to 101
South.
This tracking system allows a dispatcher to have complete and
accurate status for each vehicle, so that the dispatcher can manage
by exception with a minimum of information transmission. Management
can focus on whichever vehicles they choose, including those that
are not where they should be, making them much more effective.
The invention stresses efficiency while giving management
unparalleled control. When any of the fleet vehicles move off its
predetermined course based on predetermined rules, the dispatcher
can know it. The vehicle is immediately called and asked its
destination. A dispatched vehicle knows its destination.
Communication is minimized by down loading the waypoints and having
useful intelligence on both ends of the communication. The logic
device in the vehicle only calls if the vehicle is not on route or
on schedule.
The invention can give the fleet dispatcher a graphical and audio
picture of any equipment. It gives the dispatcher the information
as to where the transportation resources are and whether they are
loaded or empty, ambulances or fire trucks, etc.
More particularly, it is the object of the present invention to
include delivery locations as destinations. Such delivery locations
allow the user to request the nearest Radio Schack.RTM.,
Nordstrom.RTM., M.G. dealer as a destination. This allows the user
the efficiency of expending the shortest time to accomplish the
desired task.
Bookmarks stored in the central computer, at the request of the
user, allow the recording of origin destination pairs for future
fast access. For example, the user saves his home, origin, work,
and destination for future speed dial access.
The system further allows the users to determine whether mass
transit might improve their trip. The user inputs his origin and
destination. The computer calculates the shortest time route for
the user's vehicle. The computer determines if the user's origin
and destination are both conveniently served by mass transit. The
user can then be provided with the comparative shortest time mass
transit time and routing instructions.
Additional objects and advantages of the present invention are made
apparent in the following description having reference to drawings
summarized immediately hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a graphical representation, generally in the form of a
map of a selected region, typically the San Francisco, Calif. Bay
Area, having a large number of interconnecting route segments
providing alternate travel paths between a variety of selected
origins and destinations.
FIG. 2 is a graphical representation generally similar to FIG. 1
but including only the interconnected route segments with the
interconnections or nodes between adjacent route segments being
indicated by corresponding letters, the length of each route
segment being indicated numerically.
FIG. 3 is a graphical representation of an idealized region
illustrating alternate route segments interconnecting a single
origin and a single destination as a simplified means for
illustrating the method and apparatus of the invention, the
apparatus including the central computer, means for communication
with the user and the sensors providing instantly updated
information to the central computer.
FIG. 4 is a representation generally in the form of a flow chart
illustrating steps employed by a user and information flow to and
from the central computer.
FIG. 5 is a fragmentary representation of a user vehicle equipped
with a cellular telephone (or other suitable communicating means)
for communicating with the central computer of the invention.
FIG. 6 is a further representation of the selected region of FIG. 1
together with symbols indicating origin and destinations (also
termed "nodes") and corresponding names of cities, towns, for
example.
FIG. 7 represents the output of the algorithm in tabular form
including origin, destination and recommended route together with a
corresponding visual representation of the selected region similar
to FIG. 6 but with the particular origin, destination and
recommended route being highlighted (or indicated as a darkened
line) thereon.
FIG. 8 is a partially graphic and partially pictorial
representation of data illustrating the relationship between sensed
traffic velocities from sensors S1, S2, R1 and R2, etc. and the
estimated elapsed time for each of the highway segments, A, R,
etc.; a small table in the upper right corner of FIG. 8 providing a
switch of data depending upon different speed limits, for example
60 miles per hour, the switch making the minimum travel time and
distance the same in order to verify the model employed in the
central computer.
FIG. 9 is a graphical representation of historical data
illustrating the change in elapsed travel time as a result of
traffic build-up, for different departure times.
DESCRIPTION OF THE PREFERRED EMBODIMENT
As noted above, the present invention provides a method and
apparatus for determining and communicating shortest elapsed time
route information to users. The users are contemplated as traveling
between various combinations of origin and destination in a region
of the type represented by the San Francisco, Calif. Bay Area in
FIG. 1. Referring to FIG. 1, various route segments are illustrated
between interconnecting points or nodes represented by one or more
letters. FIG. 1 has been simplified in that the interconnections or
nodes are taken as various cities throughout the region in order to
simplify identification of the various route segments. For example,
A indicates Cordelia, Calif.; Z represents Milpitas, Calif.; AA
represents Santa Clara, Calif.; while DD represents San Jose,
Calif. Thus, each interconnecting route segment may be identified
by a combination of letters. For example, A-B between Cordelia and
Vallejo, Calif.; A-C between Cordelia and Benicia, Calif.; etc.
Other symbols for specific locations in the selected region of FIG.
1 are indicated for example in FIG. 6.
Numerical routes designations are also indicated for different
highway segments in FIG. 1.
FIG. 2 illustrates the same interconnecting nodes or cities with
the same route segments represented in the same manner described
above with reference to FIG. 1.
The method and apparatus of the invention can probably best be
described by reference to the simplified or stylized grid for a
region represented in FIG. 3. In FIG. 3, the interconnecting points
or nodes for a variety of route segments are represented by similar
letters A, B, C, etc., Accordingly, the various route segments in
FIG. 3 may similarly be represented as A -B, B -C, C- D, D -E, etc.
Similarly, with A and E respectively representing point of origin
and destination (at least for westbound traffic as illustrated),
then alternate paths of travel could be represented as A -B -C -D
-E and A -I -H -F -E. Other combinations are also available
including the central node G.
Continuing with reference to FIG. 3, rate of travel sensors are
positioned along each of the route segments A -B, B -C, etc.
throughout the entire grid being controlled by a central computer
indicated at 12. The individual rate sensors in one direction are
represented as S1, S2, S3, S4, etc. while sensors in the other
direction are represented as R.sub.1, R.sub.2, etc. Preferably, a
plurality of rate sensors are arranged along each of the route
segments in order to provide a more accurate reflection of rate of
travel along the respective route segments. As illustrated in FIG.
3, two such rate sensors are positioned along each route segment.
However, different numbers of sensors could be employed on
different segments, for example if the different route segments are
of different length of if they include different numbers of
locations representing possible points of conflict for traffic.
In any event, the individual rate sensors S1, S2, etc. are all
interconnected with the central computer 12 so that the central
computer 12 has continuing access to instant rates of travel for
all of the route segments in the grid being controlled by the
central computer 12.
The individual rate sensors S1, S2, etc. may take a variety of
forms. For example, the sensors could be radar or infrared based
detectors of a type commonly employed for monitoring vehicular
rates of travel. Probes could be sending back changes in position
or velocity or elapsed time between points. Proper interconnections
between the sensors and the central component 12 provide the
computer not only with the rate of travel at each point but also,
if desired, the number of vehicles traveling past that point at any
given time interval. Additional useful route information will be
provided to the user.
Preferably, the rate sensors S1, S2, etc. comprise electronic loop
detectors by a type embedded in the roadway for all lanes of travel
at each detection point, the computer can analyze each lane
separately to provide for high occupancy vehicle (HOV), truck lanes
etc. Detectors of this type are described in greater detail, for
example, in U.S. Pat. No. 4,680,717 issued Jul. 14, 1987 to Martin.
The detectors of that patent may be employed for monitoring traffic
volume, for example, and multiply or in pairs for monitoring
traffic velocity. The actual construction and operation of the rate
detectors are not an element of the present invention except for
performing their conventional function of monitoring rates of
travel for traffic at each of the sensor points S1, S2, etc.
Accordingly, the construction and method of operation for the
sensors are not described in greater detail. However, the above
noted patent describing such sensors in greater detail is
incorporated herein by reference as though set forth in its
entirety to provide greater information if desired.
The central computer 12 is adapted for simultaneously receiving
large amounts of information and calculating and transmitting
shortest elapsed time route information for large numbers of
origin-destination combinations to a corresponding number of users.
Here again, the specific selection and method of operation for the
central computer 12 is not a specific feature of the present
invention. However, it is generally noted that computers of the
type described in the patent references above would also be
generally satisfactory for purposes of the present invention. In
that regard, characteristics of the central computer such as
operating speed, data storage capacity, etc. are in large part a
function of the complexity of the region to be regulated by the
computer.
Finally, means are also contemplated for providing communication
between the central computer 12 and large numbers of users, one
such user being represented by a vehicle indicated generally at
14.
As noted above, wire-tied telephones 22 could be employed for this
purpose. However, in that event, it would be necessary for each
user to contact the central computer 12, probably prior to
commencing travel between a selected origin-destination
combination.
For that reason, the invention preferably contemplates means such
as mobile devices, i.e., radio, fax, pager, data terminal,
satellite connection or cellular telephone for providing
communication between the central computer 12 and each user vehicle
such as that indicated at 14. Accordingly, the central computer 12
is preferably coupled with a mobile telephone broadcasting station
16 while each vehicle user 14 is provided with a cellular
telephone, represented by the antenna 18, for maintaining
communication with the central computer 12 by means of the mobile
telephone station 16. In addition, it is contemplated that the
vehicle 14 may be equipped with a GPS unit which continuously looks
to satellites and its own algorithms to determine the latitude and
longitude of the vehicle 14.
Here again, the construction and mode of operation for the mobile
or cellular telephone is not a feature of the invention as such,
only the function of the cellular telephone system in maintaining
communication between the central computer 12 and each vehicular
user 14. However, a cellular radio telephone system of the type
contemplated by the present invention is disclosed for example in
U.S. Pat. No. 4,144,411, issued Mar. 13, 1979, that reference being
incorporated herein as though set forth in its entirety to provide
additional information as necessary or desired for a more complete
understanding of the invention.
Additionally, the construction and mode of operation for the GPS
unit 15, is not a feature of the invention as such, only the
function of the GPS unit maintaining its current coordinates and
communicating them to a logic device, 17 and hence to the central
computer 12.
It is noted that the individual sensors S1, S2 may also be placed
in communication with the central computer 12 by telephone or other
means. Since the sensors are immobile, it is contemplated that they
are preferably interconnected with the central computer 12 by the
most cost-efficient method available generally represented by
broken lines at 20. Probes would communication by mobile devices
similar to the system users and in fact may be system users.
Thus, the central computer 12 is in continuing communication with
all of the sensors (tag readers) S1, S2, etc. as well as any number
of users such as the user/probe vehicle represented at 14. With
such a combination of apparatus, the invention is contemplated for
operation in a method described immediately below.
Very generally, it is contemplated that the central computer 12
receive continuing instant rate of travel information from all of
the rate sensors (tag readers) S1, S2, etc. and probes 14 so that
the central computer 12 has immediate access to rates of travel
along all of the route segments A -B, B -C, etc.
With that rate information available, the individual users such as
the vehicle user 14 then contact the central computer 12 and
request the shortest elapsed time route for any given
origin-destination combination, for example A -E in FIG. 3. The
central computer 12 is immediately capable of calculating all
possible combinations and immediately communicating to the
individual user the preferred or shortest elapsed time route for
the requested origin-destination combination.
It is further contemplated that the central computer 12 is capable
of storing information regarding each user, preferably for a
predetermined period of time corresponding to the contemplated
travel time for the user. With the user being in continuing
communication with the central computer 12, for example by means of
mobile radio telephone as described above, the central computer 12
is then capable of providing updates as necessary to the individual
user if necessary for adjusting or altering the shortest elapsed
time route for that user. The user's current change in position,
latitude and longitude, can be used as a probe. In addition, the
current position in conjunction with the route can be used by the
dispatcher.
It is the current practice to label all the intersections in an
area as nodes, and attach to them their geographical location
(their latitude and longitude). The current practice further
describes the highway between the nodes and calls them arcs. When
the computer 12 calculates the shortest time route, the nodes along
that route are called waypoints.
At the same time, the central computer 12 is also contemplated as
including historical data illustrating normal rates of increase or
decrease in travel time along each route segment depending upon the
time of day, day of the week and month or year, etc. With such
historical information the central computer 12 is then capable of
making adjustments in the shortest elapsed time route for each
user. For example, the central computer could use such historical
data either for varying the shortest elapsed time route if
necessary or for providing the user with a minimum travel time and
route between the respective origin and destination. In other
words, the invention provides the user with information
statistically comprising the best or minimum elapsed time and route
between any combination of origin and destination. Since the
computer provides that information before the user actually travels
along the recommended route, the recommended route is, in effect,
based on probability. The probability of the recommended route
providing the shortest elapsed travel time is enhanced when the
instantly monitored rates of travel on the different route segments
are adjusted by historical data, censored and probe data referred
to above and described in greater detail below. Generally, the most
accurate predictor of elapsed time now is the sensed velocities;
two hours from now the probability based most accurate velocity is
one hundred percent historical patterns. The central computer
calculates the least time route based on giving weight to sensor
data in the near horizon and historical in the far horizon. This
feature is part of the refinement that allows the computer to
suggest a time of departure based on a required time of
arrival.
It will be obvious that the central computer 12 may also have
additional capabilities. For example, for users such as delivery
services and the like, data may be supplied for multiple or even
large numbers of user vehicles, possibly with different
origin-destination combinations, etc. Furthermore, the central
computer 12 could also be adapted to provide shortest elapsed time
routes for multiple destinations, for example, if an individual
user wishes information as to the shortest time for traveling to
multiple addresses, either in a particular order or in an order
determined by the central computer.
The method of operation contemplated by the present invention is
described immediately below with particular reference to FIG.
4.
The method of the invention is believed to be best understood by
the following user sequence indicating information conveyed to the
central computer by the user and interactions of the computer with
the sensors and other means for selecting and conveying to the user
a recommended route and estimated minimum travel time between
selected points of origin and destination.
An exemplary user sequence is set forth below, assuming that the
method of operation and apparatus for the present invention are
adapted for telephonic communication between a user, either from a
wire-tied telephone or from a mobile device or cellular telephone
in the user vehicle, for example.
This example of a user sequence is set forth only for purposes of
more completely demonstrating the invention and is not to be
considered a further limitation on the method and apparatus of the
invention. Furthermore, the exemplary user sequence is described
particularly with reference to the schematic illustration in FIG. 4
and also with reference to FIGS. 1 and 2. In that regard, the
exemplary user sequence is further contemplated particularly for
use within the user region illustrated in those figures.
Accordingly, the user sequence refers to specific locations or
nodes, numerical route designations, etc. for that particular user
region.
Exemplary User Sequence
User Dials: 902.sup.(1)
Computer Response: "You have reached traveler information services
for the Bay Area. This service provides route recommendations to
minimize time in route. Please key in the first letter of the
origin city followed by the pound sign (#) and highway number
without a prefix or type the highway numbers of the highway
intersection nearest your origin. For example, if your origin is
Benicia on Interstate 780, type B#780 or type
#680#780.".sup.(2)
User Dials: The first letter of the city followed by #, then the
highway number. For example, the caller's origin is Walnut Creek on
highway 24. The caller dials W#24 or 24#680.
Computer Response: The computer acknowledges the caller's input by
repeating "Your origin city is Walnut Creek. If that is correct,
press 1; if not, press 2."
User Dials: 1.
Computer Response: Computer acknowledges yes by asking: "Place key
in the first letter of your destination city, then the # sign and
highway number without a prefix, or type the highway numbers of the
highway intersection nearest your destination." If there had been
more than one city on highway 24 with the first letter W, the
computer would ask the user to choose between the cities which the
computer would list with first letters starting with W, X or Y.
User Dials: The first letter of the city followed by #, then the
highway number. For example, the caller's destination is Sunnyvale
on highway 280; the caller dials S#280 or #280#85.
Computer Response: The computer determines that there is more than
one city on highway 280 with the first letter S. The computer asks
the use to choose between the cities listed with first letters
starting with P, R or S. The computer then states, "If your
destination is Palo Alto, dial 1; San Mateo, dial 2; Sunnyvale,
dial 3."
User Dials: 3.
Computer Response: The computer acknowledges the caller's input by
repeating: "Your destination city is Sunnyvale. If that is correct,
press 1; if not, press 2."
User Dials: 1.
Computer Response: The computer accesses the minimum elapsed time
and route matrix partially illustrated in Tables I and II and tells
the user. "The estimated elapsed time to destination is (time
stated) and the recommended route is (route stated). If you would
like the names of the cities in route, type 1; for points of
interest in route, type 2; for hotels, type 3; and for names of
off-ramps, type 4."
(1) The user sequence is described employing the dialing code 902
contemplated, for example, for use by occasional users or visitors
from other regions. Such users may be less familiar with the
particular region, for example, and the computer can be adapted to
provide additional detail. Other dialing codes may be employed for
other classes of users. For example, another dialing code such as
"903" could be employed for commuters who are very familiar with
the region. Still another dialing code, for example "904" could be
employed for yet another class of drivers such as truckers or
drivers of commercial vehicles to provide them with information
particularly adapted for their needs. Note that these various
dialing codes are also indicated with respective introduction
scripts in FIG. 6.
(2) If the computer can not identify the user's anticipated origin
and destination combination, the user is asked to repeat the input
or to dial for operator assistance if necessary.
NOTE: a.) The origin for a mobile telephone may be assumed as the
then location of the mobile user vehicle assuming it is practical
for the cellular phone company computer to identify origins.
Alternately, the origin may be determined from a GPS device located
on the vehicle or a sensor(tag reader) located adjacent to its
path. b.) Some telephones and some watches have telephone number
storage capabilities. Some phones and watches allow a note or a
name to be keyed in by repeatedly punching a number and the display
change. Phones and pagers have a display that may be utilized in
some way including text messaging. These features could be used for
example in the user sequence, if available. c.) An operator may be
used just like directory assistance. The operator listens to town
of origin and destination and then keys the code on the computer
linked map. The computer gives the estimated time in route, etc.
with the operator off line in the same way as with directory
assistance. This feature is particularly important for a user who
is disoriented or unfamiliar with the area. It also overcomes the
difficulty of keying information while driving or with restricted
lighting. Voice recognition is accommodated since responding B, L,
0 in spelling a cross street can replace keying them. Recognizing
Bloomfield as a street without spelling is anticipated.
d.) Note that FIG. 9 illustrates one type of historical data which
may be employed for providing more accurate information to the user
depending upon the user's contemplated departure time. With such
historical information including the velocities recorded by
sensor/probe which capture traffic patterns being available, the
user could be asked by the computer to indicate departure time if
the user is not commencing travel immediately. Then, either for
immediate departure or for delayed departure, the computer could
factor in historical data of the type illustrated in FIG. 9 in
order to provide a more accurate assessment of elapsed travel time
and possibly the recommended route. Historical patterns captured
make it possible to give different weight to censored and
historical information depending on how much in the future it will
be used. For a route in progress the censored/probe velocities are
probably the most accurate indication of elapsed time near the
current position but for a trip that has two hours remaining
historical patterns for the end of the trip are the best
predictor.
e.) The above user sequence is set forth based upon anticipated use
of audio transmission or communication between the user and the
central computer. For example, such a communication link could be
provided by wire tie telephone or by mobile or cellular telephone
as noted above. It is also to be noted that communication between
the user and the central computer could employ video and/or data
transmission. Suitable video receive/transmitters could be provided
in the user vehicle either in the form of a facsimile machine, data
display terminal, or even a video screen, similar to a television
screen or otherwise. Such video transmitters or receivers would be
of particular value since they could specifically display a
recommended route for the user and the user could retain that
recommended route display for further reference during travel. The
GPS logic devise 17 will have the ability to compare waypoints to
give information to the user such as video display of current
location. The GPS current vs. turn location can provide a countdown
to turns to give appropriate audio and/or video notice to the user.
Thus, the vehicle user 14 illustrated in FIG. 4 could be provided
with such a video transmitter/receiver in place of or in addition
to the mobile or cellular telephone indicated at 18.
Table I set forth below illustrates minimum elapsed time between a
portion of the origin points and all of the destination points
illustrated in the selected user region of FIGS. 1 and 2. In
practice, the data illustrated in Table I would be complete for all
possible points of origin, as illustrated here, or by performing
the calculation for only the requested origin/destination. Which
alternative procedure will be used largely depends on computer
calculating vs. look-up time.
TABLE I Origin DES- TI- NA- TION A B C D E F G H I J K L M O P A 0
20 24 36 28 41 43 60 56 53 62 67 71 96 100 B 16 0 24 27 8 22 34 43
37 34 42 47 51 77 80 C 25 9 0 12 17 31 19 36 41 43 51 56 60 86 89 D
35 19 10 0 16 30 7 24 29 33 51 47 51 82 89 E 25 9 29 19 0 14 26 35
29 26 34 39 43 69 72 F 37 21 41 31 12 0 34 21 15 12 21 26 30 55 59
G 47 31 22 12 28 40 0 17 22 26 60 39 43 69 72 H 60 44 35 25 35 23
13 0 5 9 43 22 26 52 55 I 55 39 41 31 30 18 19 6 0 4 38 18 22 47 51
J 51 35 44 34 26 14 22 9 3 0 34 14 18 43 50 K 61 45 65 55 36 24 58
45 39 36 0 50 54 79 83 L 62 46 55 45 37 25 33 20 14 11 21 0 4 30 33
M 66 50 60 50 42 30 38 24 18 16 26 4 0 26 29 O 88 72 82 72 64 52 60
46 40 38 48 26 22 0 7 P 92 76 86 76 68 56 64 50 44 42 52 30 26 6 0
Q 108 92 102 92 84 72 80 66 60 58 68 46 42 20 27 R 64 48 43 33 39
27 21 8 9 13 47 27 31 48 55 S 88 72 67 57 63 51 45 32 33 37 71 51
53 31 38 T 85 69 64 54 60 48 42 29 30 34 68 48 52 31 38 U 91 75 70
60 66 54 48 35 36 40 72 50 46 24 31 V 105 89 80 70 85 73 58 54 55
59 82 60 56 34 40 W 71 55 46 36 52 64 24 41 46 50 84 63 67 51 58 X
95 79 70 60 76 88 48 65 70 74 98 4 72 50 56 Y 97 81 72 62 78 85 50
66 67 71 94 6 68 46 52 Z 105 89 80 70 86 93 58 74 75 79 102 14 76
54 60 AA 116 106 91 81 95 83 69 77 71 69 79 25 53 31 38 BB 117 101
92 82 98 100 70 86 87 86 96 26 70 48 54 CC 136 120 111 101 115 103
89 97 91 89 99 45 73 51 58 DD 126 110 101 91 107 109 79 95 96 95
105 35 79 57 63
Table II contains generally the same data described above for Table
I. In addition, Table II illustrates a recommended routing with
minimum elapsed travel time between a given point or origin and
point of destination. For example, if a point of origin is assumed
to be Cordelia (A) and the destination Belmont (P), then the
recommended route is determined by the computer, commencing at the
destination and working backwards as illustrated sequentially from
P to M, M to L, L to J, J to F, F to E, E to B and B to A. The
manner in which the computer selects this particular sequence will
be readily apparent from FIGS. 1 and 2, based upon the various
interconnecting segments between the nodes intermediate the point
of origin, Cordelia (A) and the point of destination, Belmont (P).
Table II also illustrates the preferred manner in which an
algorithm described in greater detail below, operates to select or
determine a minimum route in concentric layers beginning at the
destination and working back to the point of origin for each
user.
TABLE II Origin DES- TI- NA- TION A B C D E F G H I J K L M O P A *
B C C B B C C B B B B B B B B A * C C E E C E E E E E E E E C A B *
D B B D D D D B D D D B D C C C * E E G G G G E G G G G E B B B D *
F D F F F F F F F F F E E E E E * J J J J K J J J J G D D D D D H *
H H H H H H H H H G I G G I I G * I I I I I R I I J J H H J J R H *
J J J J J J J F F I I F F I I I * F L L L L K F F F F F F F F F F *
L L L L L J J J J J J J J J J K * M M M M L L L L L L L L L L L L *
O P O M M U U M M U U M M M M M * P P M M M M M M M M M M M M M O *
Q V V V V V V V V V V O O O O O R I I H H I I H H I I I I I T T S I
I T T I I T T I I I I I U U T R R R R R R R R R R R R R U U U T S T
T S T T T T S S S O O O V U U U U U U U U U U U U Q Q Q W G G G G G
T G T T T T T T T T X W W W W W W W W W W Y Y Y Y Y Y X X X X V V X
V V V V X V V V Z Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y AA Z Q Z Z Q Q Z Q
Q Q Q Z Q Q Q BB Z Z Z Z Z Z Z Z Z Z AA Z AA AA DD CC AA AA AA AA
AA AA AA AA AA AA P AA P P P DD BB BB BB BB BB BB BB BB BB BB CC BB
CC CC CC
The method and apparatus described above are thus believed to
provide a complete disclosure of the invention, particularly with
reference to the selected region illustrated in FIG. 1 and
elsewhere.
A more detailed example of the method contemplated by the present
invention is set forth below, including specific algorithms, etc.
for a specific region such as that illustrated in FIGS. 1 and 2.
That method is described as follows.
A typical algorithm adapted for use in the central computer is set
forth below as an exemplary means of clarifying both the method and
apparatus of the present invention as described above.
The algorithms is based on the real time information fed into the
sensor table (FIG. 8). In this table, the elapsed times for each of
the highway segments are calculated. The raw sensor data
represented by S1 and S2 for the highway segment running between
node X and node Y will be correlated with actual time of auto
probes running between the nodes under various conditions for
calibration purposes and correlation equations developed. S1 and S2
will collect not only velocity data but traffic volumes. S1 and S2
may also function as tag readers transmitting the tag number; as a
vehicle passes S1 and then passes S2, the central computer
calculates velocity. All data will be used in multiple correlation
and physical flow models to create the most accurate prediction
possible. These equations will be updated as additional data
becomes available. Based on these equations, the ETxy and the
reverse direction ETyx will be calculated on a continuous
basis.
The next step is to calculate the minimum time between nodes. The
results of this calculation are shown for the Bay Area in Table I.
Please refer to FIG. 3. This figure will be used for the purpose of
explaining how minimum elapsed times are calculated. For example,
assume E is the destination and F is the origin. The minimum time
is min(FE or Min(FHIG,FG)+Min(GBCD,GD)+DE). These letters represent
the routes and the sum of the segment times. Minimum is stored in
FE. Min for D to E is obtained next as min(DE or
Min(DCBG,DG)+Min(GIHF,GF)+FE) and is stored in DE.
The next step is to get the minimum routes for C, G, and H to E.
Next solve for GE, its equation is the min(min(GD, GBCD)+DE or
min(GF,GIHF)+FE). This is stored in GE. Next solve for CE, the
min(CD+DE or CBG+GE). The equations are now getting simpler because
the minimum paths have been established for many of the paths to
the destination. The second element that helps is that after all
the origins to one destination have been determined to Excel or
similar spread sheet type programs, the indexing of equations from
column to column make the necessary changes automatically except
for the first or possibly the second layer of nodes away from the
destination.
The next portions is to keep track of the route. This is done by
keeping track of the direction from which the minimum path route
came. Then the path is figured back to the origin as illustrated in
Table II.
The final step of the algorithm provides for adjustment and
possible change of the elapsed time and recommended route depending
upon historical factors such as traffic build-up represented in
FIG. 9 and also set forth below in Table III. Table III includes
historical data typically based upon monitoring of traffic velocity
over a period of time, preferably weeks, months or even a year in
order to accurately assess periods of traffic build-up or decline
which can be readily predicted.
In that target, Table III represents historical build-up or decline
of traffic particularly during rush hours extending for example
from 6:00 a.m. through 9:15 a.m. and from 3:00 p.m. through 6:30
p.m. In Table III, military times are employed to facilitate use of
the information by the computer.
TABLE III Time of Time of Day ETxy F(b) Day ETxy F(b) 6:00 20 1.00
15:00 20 1.00 6:15 20 1.00 15:15 20 1.00 6:30 22 1.10 15:30 22 1.10
6:45 25 1.14 15:45 25 1.14 7:00 30 1.20 16:00 30 1.20 7:15 33 1.10
16:30 33 1.10 7:30 35 1.06 16:45 35 1.06 7:45 35 1.00 17:00 35 1.00
8:00 35 1.00 17:15 35 1.00 8:15 33 .94 17:30 33 0.94 8:30 28 .85
17:45 28 0.85 8:45 25 .89 18:00 25 0.89 9:00 22 .88 18:15 22 0.88
9:15 20 .91 18:30 20 0.91 1.00
Table III is thus only one example of historical data which may be
employed in the algorithm of the present invention. Other types of
historical data may also be employed. For example, predictable time
periods of traffic build-up or decline may be predicated upon
factors other than rush hour traffic during normal work weeks as
represented in Table III. Other types of historical data are
provided for holiday schedules and other known events, such as
sporting events, tending to have a predictable impact upon traffic
flow.
Referring again to Table III, current time, t, may be stored within
the computer program or algorithm as a decimal portion of a day
corresponding, for example, to the times of day represented in
Table III.
Then, adjustment time T=t plus ETxy. Then, if (T>6/24 and
>9.25/24,v=round((T*24-6)/4),v=1) or if (T>15 and T<18.5,
V=round (((T*24-15)/4+15), V=1). The F(6) from the Vth line of
Table III is then used in the equation. F(b) is represented in
Table III as a factor relating to the historical build-up or
decline of traffic for a particular time. For example, referring to
the values of F(b) in Table III, there is no delay factor at 6:00
a.m. or 6:15 a.m. followed by a delay factor from 6:30 a.m. through
7:30 a.m., no delay factor at 7:45 a.m. or 8:00 a.m. and then a
decline or negative delay factor from 8:15 a.m. through 9:15
a.m.
Applying the above equation, the estimated time for a given route
segment taken from FIG. 1 or FIG. 2 is stated as: ETxy
adjusted=ETxy*F(b). In other words, the actual delay function for a
recommended route between a selected point of origin and point of
destination equals the sum of adjusted ETxy values for all of the
route segments selected by the computer between the point or origin
and point of destination as described above.
Accordingly, there has been disclosed above a method and apparatus
for determining and communicating shortest elapsed time route
information to users. Various modifications in addition to those
specifically noted above are contemplated by the invention which
accordingly is defined only by the following claims which are
further exemplary of the invention.
* * * * *