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Patent - GPS carpool assistant

TITLE: Method for GPS carpool rendezvous tracking and personal safety verification. United States Patent 7,136,747.

ABSTRACT: Rendezvous tracking subsystem uses GPS-enabled cell phones communicating with an application server for tracking the whereabouts of carpool participants and for providing on-time status of participants en-route to designated rendezvous points. Safety subsystem can be used to verify safe arrival of participants at carpool destinations. Participants can configure safety subsystem by defining escalation rules and procedures to follow when safety critical events occur.

Full patent:


TrakRide is a mobility-enhancing wireless traveler information service providing real-time connection making assistance. Similar to bus stop "time to next bus" displays that assist transit riders, TrakRide makes carpools run more smoothly, reliably, and precisely, while off-loading time-consuming manual tasks. Relying on advanced cellular geolocation technology, TrakRide increases considerate behavior and time utilization, increasing the attractiveness of ridesharing. Patent-pending, TrakRide represents a foray into the "ITS-4-TDM" (Intelligent Transportation Systems for Transportation Demand Management) arena.

Operational Description:

A three-participant carpool encounters complex morning choreography. Each commuter travels from home to a rendezvous point (often a shopping center parking lot). From there, carpool participants board a single car for the rest of the journey. TrakRide serves as a "security blanket" for carpoolers, who typically encounter a major carpooling problem every two months, and a minor irritant about once per week. A previously independent solo commuter, who switches to carpooling, finds herself dependent on her carpool partners of uncertain reliability. TrakRide removes this uncertainty, making the carpooling experience more palatable to switchers. TrakRide provides a frequently updated graphical depiction of the status of the partners, somewhat analogous to bus stop "time to next bus" displays.

In carpooling, being on time at the pickup spot is the considerate thing to do. TrakRide monitors progress to the pickup spot, graphically highlighting laggards with red dots on-route. Thus, positive and negative performance feedback is glaringly apparent, naturally generating increased social pressure to be punctual.

Without TrakRide, improving punctuality often requires personal confrontation. Some existing carpools implement a "five minutes late cut-off rule." In the morning, if a carpooler is five minutes late to the rendezvous spot, other participants leave without the laggard. TrakRide provides a gentler method to encourage courteousness by providing a standardized, impersonal measuring system.

Of utmost importance, the data is current when a user stops at a stoplight or stop sign to rapidly scan the cell phone display - the data is "pushed" automatically. Waiting for the user to "pull" the data by phoning other members for status takes too long and is irritating to other carpool members. Most three-person "acquaintance" carpools have exchanged cell numbers for when things go awry, but none make status calls while on-route to the rendezvous point.

In addition, TrakRide facilitates the considerate action of informing other participants that the carpool will be delayed a certain number of minutes. TrakRide reduces an individual's ability to make up excuses for tardiness. Says one potential user, "I don't need a reminder to leave. I only need confirmation that others are moving reliably towards the carpool meeting point. One of my carpool participants needs special nudging about once every 10 days."

Time utilization is an issue at the end of the workday, before the evening pickup. TrakRide will also track the end of day "race" to the meeting point. Says a second potential user, "Making things a little smoother would be great. If I knew someone was running even a few minutes behind, and I'm in the middle of something, then that few minutes would buy me enough time to finish what I'm doing, rather than thinking 'Oh Gosh I have to shut down because I don't want someone to wait.'" The benefit is in knowing exactly when to shut down and reducing stress in wondering whether everyone else is shutting down.

On-route Commuter Tracking Example:

Let's take for example a three-person (A, B, and C) carpool with a one-way travel distance of about 30 miles. For the morning pickup, all three drive alone to a shopping center parking lot and then carpool from there. A, B, and C are in a daily race against time to get to the meeting point on time. Person A drives 10 minutes to the shopping center, B drives 7 minutes, and C drives 3 minutes. Scheduled pickup time at the shopping center is 7:30AM. Person A needs to leave her home at 7:20AM. She has a history of being late, so TrakRide sends reminder SMS messages at 7:10 and 7:15AM to nudge her to her car.

The handset GUI is shown in the figure below, showing snapshots at 7:20, 7:25, 7:29, and 7:32AM. Person A departs on time, but B departs 2 minutes late:

The handset display shows the previous paths that A, B, and C have taken to access the pickup point. A, B, and C all see the same display as the pickup process progresses. At 7:20, all three are on time, at home, and A is ready to depart.

At 7:25, B is still at home, even though he should have left at 7:23, so his dot his shown in red to indicate tardiness, and the carpool is shown as being 2 minutes late. A's progress towards the shopping center is apparent.

C should normally depart at 7:27, but C sees that the carpool is 2 minutes late and has another cup of coffee. At 7:29, C departs. A and B have made progress and B is still depicted as tardy.

At 7:32AM, everyone has arrived at the meeting point.