Automatic setting of variable speed limit

• US 6,693,555 B1
• Filed: 12/11/2001
• Issued: 02/17/2004
• Est. Priority Date: 12/11/2001
• Status: Expired due to Fees

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Philomin, Vasanth, Gutta, Srinivas, Colmenarez, Antonio
• Primary Examiner(s): Lieu, Julie
• Application Number:
  US10/014,230
• Time in Patent Office: 798 Days
• Field of Search: 340/905, 340/441, 340/539.1, 340/601, 340/602, 340/539.13, 701/118
• US Class Current: 340/905
• CPC Class Codes: G08G 1/096716 where the received information does not generate an automatic action on the vehicle control
• CPC Class Codes: G08G 1/096758 where no selection takes place on the transmitted or the received information
• CPC Class Codes: G08G 1/096783 where the origin of the information is a roadside individual element

Abstract

A system and method for automatic setting of a variable speed limits permits changing road conditions provides for variable speed limits at respective portions of a road based on weather conditions reported by sensor. A plurality of variable speed limit indicators are arranged at predetermined intervals along a road. Sensing report local road conditions regarding humidity, precipitation, temperature, fog, ice, snow, hail, sleet, wind, etc. A regulating unit correlates the sensed weather conditions with a predetermined speed limit for each given condition at each respective portion of the road. A matrix of a database may contain historical accident information regarding the specific location or zone of any accidents, time of day, date, temperature, precipitation, estimated speed and severity of injuries for each accident. The historical data can be correlated with the sensing of weather conditions to adjust the speed limit to a somewhat lower than otherwise value based on the historical data of a respective location. Thus, roads having previously known dangerous portions will have slower speed limits in the rain or snow than other portions reporting the same conditions. Portions of the road can be identified as a bridge, which tends to freeze before the rest of the road, and the variable speed limit reduced to reflect the additional potential hazard.

Claims

1. An apparatus for automatic setting of a variable speed limit comprising:

weather sensing means for sensing weather conditions of a road along a plurality of predetermined locations; and

regulating means for regulating a particular speed limit along each respective location of said plurality of predetermined locations, said regulating means communicating with said weather sensing means to correlate an output of said weather sensing means at said each respective location with a database comprising a matrix of speed limits according to the output of said weather sensing means for said each respective location;

transmitting means for automatically transmitting a respective speed limit for display based on one of periodic and continuous communication of weather conditions from said weather sensing means, wherein said regulating means regulates a speed limit according to historical accident data for said each respective location and weather conditions during each accident in the historical accident data.

2. A system for automatic setting of a variable speed limit, said system comprising:

a plurality of variable speed limit indicators arranged at predetermined intervals;

weather sensing means for sensing weather conditions of a road along a plurality of predetermined locations; and

regulating means for regulating a particular speed limit along each respective location of said plurality of predetermined locations, said regulating means communicating with said weather sensing means to correlate an output of said weather sensing means at said each respective location with a database comprising a matrix of speed limits according to the output of said weather sensing means for said each respective location; and

transmitting means in communication with said regulating means and said variable speed limit indicators for automatically transmitting a respective speed limit for display by a respective speed limit indicator of said plurality of variable speed limit indicators based on one of periodic and continuous communication of weather conditions from said weather sensing means, wherein said regulating means regulates a speed limit according to historical accident data for said each respective location and weather conditions during each accident in the historical accident data.

3. The system according to claim 2, the respective speed limit transmitted to said respective speed limit indicator is independent of a speed limit of a remainder of said plurality of variable speed limit indicators.

4. The system according to claim 2, wherein said plurality of variable speed limit indicators are categorized into groups based on one of geographic location, direction of traffic flow and volume of traffic.

5. The system according to claim 2, wherein said matrix of speed limits further comprises a historical accident report information identifying a number of accidents at each respective location of said plurality of locations, for each accident of said number of accidents, said historical accident report information includes at least one of:

a time of day and date of said each accident, a severity of injuries sustained, and an estimated speed of a vehicle or vehicles in said each accident, so that said regulating means includes said historical accident report information when regulating the speed limit for said each respective location.

6. The system according to claim 2, wherein said weather sensing means includes means for sensing humidity.

7. The system according to claim 2, wherein said weather sensing means includes means for sensing fog.

8. The system according to claim 2, wherein said weather sensing means includes means for sensing at least one of a magnitude and a direction of a wind.

9. The system according to claim 2, wherein said weather sensing means includes means for sensing temperature.

10. The system according to claim 2, wherein said weather sensing means includes means for sensing at least one of ice, sleet, snow and hail.

11. The system according to claim 2, wherein said weather sensing means includes means for sensing an amount of precipitation on the road for at least one of said predetermined respective locations.

12. The system according to claim 2, wherein said transmitting means also includes receiving means for communication with a weather forecasting service, said receiving means communicating an alert received from the weather forecasting service to said regulating means, and said regulating means overriding the matrix in the database for said each respective location with a second matrix according to a type of alert received by the weather forecasting service.

13. The system according to claim 2, wherein said sensing means communicate with said regulating means over a radio frequency.

14. The system according to claim 2, wherein said sensing means communicates with said regulating means over a fiber optic link.

15. A method for providing a variable speed limit comprising the steps of:

(a) arranging a plurality of variable speed limit indicators at predetermined intervals of a road;

(b) sensing weather conditions at a plurality of predetermined locations of the road;

(c) regulating a respective speed limit along each respective location of said plurality of predetermined locations by

(i) receiving weather conditions sensed in step (a);

(ii) correlating the received weather conditions with a database comprising a matrix of speed limits for said each respective location according for a plurality of possible weather conditions;

(d) transmitting the respective speed limit regulated in step (c) to said particular speed limit indicator of said plurality of variable speed limit detectors; and

(e) displaying by said particular speed limit indicator the particular speed limit transmitted in step (d), wherein the correlating recited in step (c) (ii) includes Providing said database with a historical accident report information identifying a number of accidents at said each respective location of said plurality of locations, and for each accident of said number of accidents, said historical accident report information including at least one of;

a time of day and date of said each accident, a severity of injuries sustained, and an estimated speed of a vehicle or vehicles in said each accident, so that said regulating means includes said historical accident report information when regulating the speed limit for said each respective location.

16. The method according to claim 15, wherein step (c) includes (iii) providing for a receipt of a weather alert code by a weather forecasting service;

(iv) providing priority to the received weather alert code over the received weather conditions in step (c) (i) and correlated in step (c) (ii); and

(v) providing the speed limit for said each respective location based on a predetermined value associated with the weather alert code.

17. The method according to claim 15, wherein the sensing of weather conditions in step (b) includes sensing humidity.

18. The method according to claim 15, wherein the sensing of weather conditions in step (b) includes sensing fog.

19. The method according to claim 15, wherein the sensing of weather conditions in step (b) includes sensing temperature.

20. The method according to claim 15, wherein the sensing of weather conditions in step (b) includes sensing at least one of a magnitude and a direction of wind.

21. The method according to claim 15, wherein the sensing of weather conditions includes sensing for one of ice, sleet, snow and hail.

22. The method according to claim 15, wherein the weather conditions sensed in step (b) are received in step (c) (i) over one of a fiber optic link and radio frequency transmission.