Invalidity dossier
US 6243026
Automatic determination of traffic signal preemption using GPS, apparatus and method
Current assignee: Global Traffic Technologies LLC
Added 9/23/2026, 10:32:43 AM
Active provider: DeepSeek · deepseek-flash
Patent summary
Title, assignee, inventors, filing/issue dates, abstract, and a plain-language overview of the claims.
Patent Overview: US 6,243,026 B1
Title: Automatic determination of traffic signal preemption using GPS, apparatus and method
Source: https://patents.google.com/patent/US6243026/en
Bibliographic data (as listed):
- Patent number: US 6,243,026 B1
- Application number: US09/432,693; filed 1999-11-03
- Publication/grant date: 2001-06-05
- Priority date (listed as an assumption, not a legal conclusion): 1995-05-05
- Inventors: Gary V. Jones, Kevin Judge, James C. Beck, Richard Keegan
- Original assignee: 3M Innovative Properties Co.; current assignee listed as Global Traffic Technologies LLC
- Legal status: Expired – Lifetime (anticipated expiration 2015-05-05)
- Classifications: G08G1/087 (override of traffic control, e.g. by signal transmitted by an emergency vehicle); G01S19/00, G01S19/41 (satellite positioning; differential GPS)
Purpose: To provide safe and unobstructed passage for emergency vehicles (ambulances, police cars, fire trucks) while minimizing disruption of normal traffic through an intersection. The stated goal is preempting normal traffic signal operation so emergency vehicles are not forced into dangerous maneuvers such as entering opposing lanes or running red lights.
Plain-language scope (per the excerpt): The invention resides in a traffic signal preemption system using differential Global Positioning System (GPS) measurements, plus a related method. The description identifies shortcomings in prior approaches—underground sensors/signposts, optical, audio, radio signal-strength, and beacon-based systems—including cost, line-of-sight limits, inaccuracy, installation and maintenance difficulties, and inability to adjust preemption distance. The excerpt also notes that existing systems lack provisions for preempting signals at adjacent intersections and may preempt too early, too late, or unnecessarily when a vehicle deviates or turns.
What the excerpt does not establish:
- The excerpt does not include the actual claims or full specification, so precise claim scope is not established here.
- It states the invention "resides in" a differential-GPS system but does not detail the apparatus/method steps; the text notes appendices on microfiche that are not reproduced.
- The listed priority date, assignees, and legal status are expressly flagged in the source as assumptions, not legal conclusions.
- No litigation, validity, or prior-art analysis is provided.
Generated 10/1/2026, 9:54:11 PM
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Litigation summary
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PTAB challenges
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Assignment history
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Prior art
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Obviousness
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Extensions
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Derivative works
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